Super unleaded?

[RickW]

Is there any point putting a higher octane fuel in my new Fabia?

 

A friend and I were debating it and he said there's no point. I tend to agree.

[PekoSI]

There is no benefit in using higher octane fuel for these low compression engines. Use whatever is recommended for your car. Otherwise you're just throwing money out the window...

[Brian69]

Out of curiosity what does it does on the inside of the filler cap of the 1.2 TSI (re RON)?

 

Also, a   to the A40.

Edited 31 March, 2016 by Brian69

[vels]

There is always a but...

Sorry if there is grammer/spelling mistakes - english is not my native language.

 

People always seems to think that high octane fuel is some sort of rocket fuel that will make their car into a Le Mans racer.

 

I'm actually a SAAB nutcase that has turned to Skoda for everyday driving, but in the past many years I have been around high performance turbo charged cars like the 9-3 Viggen and the discussions about high octane has been a hot topic all too often.

 

So the facts..

1.) the octane rating is not a "energy" classification, but an "anti-knock" rating.

 

Engine knocking if very common on turbo charged cars ( like the TSI ) and occours when the fuel self-ignite before the spark plugs was suppose to ignite the fuel. Remember this is combustion engines, not explotion egines - but when knocking occour a small explotion is really what happens and this is while the pistons is still moving upwards toward the upper dead point. The self-ignition of the fuel hammers on the pistons trying to make them go down while they are moving upwards.

This can be heard as a ping and shaking.

Modern cars today have knocking sensors, early types was fitted on the engine block and later types often has electronics where this function is placed with the igntion coils and spark plugs.

 

Fuel self-ignition can be caused by soot deposits in the engine ( starting to glow ) - but on turbo charged cars the compression ( the turbo compresses the intake air ) is high and often too hot because the intercoolers are to small to cool down the intake air to proper levels. Keep in mind that the air after the turbo charger can reach temperatures in the 600-800 degree celcious area.

Hot air contains less oxygen molocules than cold air, hence the intercooler. Hot intake air also contributes to a hotter combustion making it more prone to knocking.

 

As far as I can tell the 1.2 TSI 110 HP has a compression ratio at 10.5:1 which is actually pretty high and likely why it is so strong ( high torqued from 1400 rpm ) even at lower revs.

 

Engine management is able to "sense" the type of fuel you put on the car, by detecting when the engine starts to knock. When this occours engine management will force the turbo pressure down to precent further knocking since this can damage the engine, even knock a hole in a piston if severe enough.

 

Back to the but...self-ignition temperature of regular fuel 450-550 °C, Super fuel 480-700 °C

The higher torque demanded, the higher temperature, higher turbo pressure, hotter air..

 

So if you got a heavy foot, running on hot summer days or just like to cruise at low revs... high octane fuel might not be a bad choice or a waste of money.

 

Since gaosline in it self has a octane number around 60, its required to add "something" with very high ocatane rating - in the old days MTBE ( very toxic ) and now likely ethanol or isopropanol.

The drawback to this is that the higher octane additives has less energy when burned, so 1 liter of RON 95 will in most cases contain more energy than 1 Liter 99 RON.

 

Many people can't grasp howcome their car often has better millage on 99 Octane fuel than 95.

This is in most cases caused because the fuel is put better to use, since the engine can reach higher torque at low revs without knocking, pulling every inch of energy out of the fuel where the 95 or 92 octane fuel would not allow the engine to do the same hence wasting fuel, demanding higher revs for the same performance and more fuel.

 

In theory and put to the test, I believe that the 1.2 TSI 110 HP might deliver 5-10 HP more on high ocantane than on 95 - but only in the "extremes". Meaning at low revs your would meassure some amount of higher torque and on high revs some amount of higher horse powers.

 

On the 9-3 Viggen with it's 2.3L High performance turbo charged engine there was a clear difference on hot summerdays when running high octane. I would not expect the same of the rather small 1.2 TSI.

My best guess would be better milage with the same driving style.

 

I hope this makes some sort of sense :-)

Edited 31 March, 2016 by vels

[rum4mo]

vels, I think that you should be running a SAAB 96 or 95 and using regular unleaded with added lead substitute!

 

I have a friend that has one - he has owned maybe 20 or more SAAB 96 and 95 V4 - that 96 is a Sunday/Funday car, he has also owned a few 99, 900, 9000 9-3 and now a 9-5.

 

He still hopes and dreams for the day that the SAAB name will be back on a new proper car, a tip to other car manufacturers, do not even think about becoming part of GM as they will destroy you!

[bigjohn]

Memories - loved my Saab CS 9000

 

Out of interest I always feed my Superb 1.4 tsi and Octavia 1.416v with higher octane petrol. When driving my "new" 2001 Octavia 1.416v I could just detect a little pinking (I have good hearing and there is less sound proofing on the old car) . Car was checked but everything OK. I swapped to high octane petrol and have since done 120k miles on this engine with no issues . The 1.4 16v had many forum reports of pistons failing at low mileages, petrol related possibly/ possibly not but I don't take any chances. On my Octavia it seemed to make a slight improvement in MPG but probably not enough to cancel out the extra cost. 

 

My Superb tsi is far too well soundproofed to hear pinking so I'll use higher octane fuel anyway when possible - just in case

 

Shell Vpower seems to have become mega expensive now so I usually use Tesco Geenenergy now

Edited 31 March, 2016 by bigjohn

[RickW]

Out of curiosity what does it does on the inside of the filler cap of the 1.2 TSI (re RON)?

 

Also, a   to the A40.

It says 'Min. 95 RON Super Unleaded',that's the recommendation for my Fabia.

 

My Austin A40 has to have a Castrol lead additive each time I fill up with unleaded.

[vels]

vels, I think that you should be running a SAAB 96 or 95 and using regular unleaded with added lead substitute!

 

I have a friend that has one - he has owned maybe 20 or more SAAB 96 and 95 V4 - that 96 is a Sunday/Funday car, he has also owned a few 99, 900, 9000 9-3 and now a 9-5.

 

He still hopes and dreams for the day that the SAAB name will be back on a new proper car, a tip to other car manufacturers, do not even think about becoming part of GM as they will destroy you!

 

rum4mo :-)

 

The Saab 9-3 Viggen is entirely another beast and can't be compared to the old V4 or two strokes - maybe you should google it :p ( I actually have a old 1956 twostroke ).

The stroker only needs oil and the V4 can be modifyed with new valve seats that makes it compatible with unleaded fuel if your friend has these concerns.

 

But...what I should be running a SAAB on was not really a part of the discussion, I only mentioned it because SAAB and turbo charged engines has been around long before the VW group started using it to the general public.

So the point was really just to transfer some of the experiences and research from that part to these new small Turbo charged engines.

 

Point being... high octane fuel might not be a waste of money - it just depends on your driving style and personal preference.

[rum4mo]

Yes, I know, just a flippant switch away from the topic, my friend did manage to stay smart and avoid any of the "better" SAAB variants as he uses them as a daily runner and buys them at about 100K miles old!  With the mileage he will be running with his 96, he will be cheaper sticking to UL and adding the Castrol additive - which I found that a service station was selling off cheap, £5 for two containers of it!! Another thing SAAB did was share the Triumph 1709cc engine and sort it out, something that Triumph never did, not even when making it up into a V8 in the Stage!

 

The UL v UL+ discussion never comes to a happy end, I've used it to cover up a problem quite successfully, but I knew it was costing me dear but made that car run a lot better with lots more low end drivability. I now tend to stick with what the manufacturers suggests and only use "proper" fuels from well establish fuel companies.

 

Back on topic!

 

Edit:- I am old enough to remember seeing the early turbos being used in WRC - well RAC rally of Great Britain as it was then, all you could hear was stones hitting off the underside of the SAABs, Ford Escorts etc were all engine noise and sideways action!

Edited 31 March, 2016 by rum4mo

[vels]

Memories - loved my Saab CS 9000

 

Out of interest I always feed my Superb 1.4 tsi and Octavia 1.416v with higher octane petrol. When driving my "new" 2001 Octavia 1.416v I could just detect a little pinking (I have good hearing and there is less sound proofing on the old car) . Car was checked but everything OK. I swapped to high octane petrol and have since done 120k miles on this engine with no issues . The 1.4 16v had many forum reports of pistons failing at low mileages, petrol related possibly/ possibly not but I don't take any chances.

 

Shell Vpower seems to have become mega expensive so I usually use Tesco Geenenergy now

 

 

Hi John,

 

On that particular engine, what you likely hear is the piston rings.

This also makes at "pinking" or "ringing" noise... I've heard this should mostly be related to the engine blocks designated AUB.

 

I've seen people say that engine will survive on high ocatane fuel, but I really can't tell the truth in this.

If the rings are bad, they are bad and it will consume more and more oil - smoke and at some point break down if the nature of the problem is not taken care of ( new piston rings ).

 

At most I think high octane fuel in this case can prolong the engine life because it will not self ignite and cause knocing because of the soot deposits that will occour when the piston rings are not ok.

Less knocing equals longer life to the pistons and piston rings... but a cure, not really.

 

Engines from this period of time is a generation where the manufactures experimentet med lower friction and longer service intervals on less oil.

Many engines from the period of time died due to oil sludge, blown piston rings and extreme levels of oil consumption.

 

If you are nervous about it then get your local mechanic to do a compression test or oil test leak test.

[Flopsy]

according to this motoring writer in UK there are definite benefits in using the premium petrols; here's an example of one of his answers http://www.honestjohn.co.uk/askhj/answer/23103/which-fuel-

He gets asked this question fairly regularly and has many years experience in the motoring industry(not the petrol one).

[bigjohn]

Hi John,

 

On that particular engine, what you likely hear is the piston rings.

This also makes at "pinking" or "ringing" noise... I've heard this should mostly be related to the engine blocks designated AUB.

 

I've seen people say that engine will survive on high ocatane fuel, but I really can't tell the truth in this.

If the rings are bad, they are bad and it will consume more and more oil - smoke and at some point break down if the nature of the problem is not taken care of ( new piston rings ).

 

At most I think high octane fuel in this case can prolong the engine life because it will not self ignite and cause knocing because of the soot deposits that will occour when the piston rings are not ok.

Less knocing equals longer life to the pistons and piston rings... but a cure, not really.

 

Engines from this period of time is a generation where the manufactures experimentet med lower friction and longer service intervals on less oil.

Many engines from the period of time died due to oil sludge, blown piston rings and extreme levels of oil consumption.

 

If you are nervous about it then get your local mechanic to do a compression test or oil test leak test.

 

I'm not nervous about this as I have previous form from my misspent youth rebuilding / restoring cars and "tweaking" engines. The Ford Essex V6 (2.5 & 3.0) was a speciality! 

 

My Octavia has done this from new (took it back initially) - basically if you use 95 ron it pinks (very faint) if you use 99 ron it doesn't - so I use 99 ron

To be honest many people wouldn't hear this - but I'm sensitive to any car noises. 

 

The car is running extremely well (surprisingly nippy) and It has been very reliable and still doesn't need topping up with oil between services (ignoring a couple of journeys after which I discovered the oil breather had become blocked!). 

 

On my other car the Superb  tsi I'm not sure I could hear it though (probably isn't present ) as it's so well soundproofed .  I'll just play safe with 99ron Greenenergy! I'm also pleased with my fuel economy - will never find out if worse on 95 though

Edited 31 March, 2016 by bigjohn

[alltorque]

Had a Volvo S60 D5 185bhp for 8 years and 100k+ miles and fed it Shell V-Power Diesel. In al that time it ran wonderfully, would pick up its skirts and fly if asked, never used oil and, never gave any hint of DPF problems and always gave very low EXHAUST opacity readings at MOT...the last one, in my ownership, being 0.01. The old girl is still running lika dream with its new family.

My Fabia 1.2/110 TSI has been fed with Shell V-Power Nitro+ from new and now, at 5k+ miles, it is a joy and reminds me so much of my old Mk1 vRS in the way it goes.

Am I wasting money on fuel? I don't think so, but I'd be hard pressed to prove it. Having worked in the oil industry for many years I do not buy anything other than major brands...even though the brand name on the pump might not match the refinery it came from, (few refineries and lots of distribution exchange deals), but I never buy "Supermarket" fuels unless I know who the actual suppler is.

My money, my choice.

[Ootohere]

You can be sure that Tesco Momentum 99 (99 Ron Minimum) is Produced and supplied by 'Greenergy'. that work in partnership with Royal Dutch Shell with Importation Ports and Refineries and Distribution Depots.  Shell V-Power Nitro+ also being 99 ron minimum in the UK.

Momentum is 5 pence a Litre more than Tesco Unleaded 95 ron, and Shell is however much more than the Retailer sells it.

Both are 99 Ron Minimum, and may be a higher octane on occasion, location, location, location and market dependant as Imported.

Greenergy also Produce and Distribute to Esso Filling Stations in Scotland and other Area of the UK.

 

As to the other UK Super Unleaded Sellers, they have 97 ron Minimum, ie, Sainsburys, Esso, BP, Texaco, Gulf etc.

 

Supermarket filling stations do not get some rubbish fuel from some Back Street Refinery or Fuel Depot, 

it meets the Minimum Standard and sometimes exceeds it, depending on where in the market they buy and when.

 

http://platts.com/latest-news/oil/london/uk-still-buying-winter-gasoline-as-european-refiners-8114744

Year to year at UK Filling stations you might not know what or where the 95 ron Unleaded or Super Unleaded is, other than meeting the Standard required.

As to secret additives, detergents are sodium based, not so secret really.

 

PS.

The best way to decide if paying just £2.25 extra a tank fill for Tesco Momentum 99, or around £4 for Shell V-Power Nitro+ is to brim your tank and try it once you are into a routine and the car is run in a bit & you know what miles per tank you are getting on 95 ron Unleaded.

Maybe try Sainsburys 97 ron which again is about £2.25 a tank extra.

The additional cost equal to around buying 2 litres of Unleaded might well be worth it if you feel the car performs better, and if it does more miles per tank it will have paid its way.

Edited 2 April, 2016 by GoneOffSKi

[Guest]

Is there any point putting a higher octane fuel in my new Fabia?

 

A friend and I were debating it and he said there's no point. I tend to agree.

 

Rick, I'm an ex-tech and engine designer. Using too higher octane is not recommended for any car not designed to run on it. High octane should only be used in higher performance vehicles. Most modern engine that are NOT designed to run on it won't benefit and it will in fact actually harm your fuel economy and performance. It also leads to higher soot content in the engine. I've dyn'oed many engine in my time as an engineer and unless it's a high performance engine the power output always went down from the manufacturers figures, yet owners were adamant the engine ran better! It didn't and we proved it. Modern engine are designed to cope with differing grades of fuel, but putting say 99ron in a 1.2tsi will have this negative effect. The 1.2TSI actually runs best on 95ron. The ecu won't be able to fully compensate for much higher that usual octane rating (say 99ron) for that fuel. Higher octane fuels need longer to burn and this means advancing the ignition and fuel injection timing, amongst other things. Because the ignition won't be able to be advanced enough, the fuel will still be burning at BDC thus wasting some of that charge's power. It also means the exhaust gases will still be very hot and maybe still burning as it exits the exhaust port. Thus is causes more dirt/carbon on the valves and in the ports. It also can damage the cylinder head valves and seats. It's well documented in lots of technical online sites and has been known about for years and years. Not saying that if you put in some high octane because you can't get anything else that it will harm your motor. It won't, but running it on high octane unnecessarily long term most likely will. It also depends on how you drive the car as to how much harm could be done on high octane.  Below is a link to a not very technical article (it's easy to read for non technical types) and it's an article from the states showing different octane readings on the pumps but it's a completely valid article. If you want more technical stuff just google it...

 

http://www.whatcouldbegreener.com/142/fuel-octane-choosing-the-wrong-octane-will-cost-you/

Edited 3 April, 2016 by Estate Man

[Gazbull17]

Rick, I'm an ex-tech and engine designer. Using too higher octane is not recommended for any car not designed to run on it. High octane should only be used in higher performance vehicles. Most modern engine that are NOT designed to run on it won't benefit and it will in fact actually harm your fuel economy and performance. It also leads to higher soot content in the engine. I've dyn'oed many engine in my time as an engineer and unless it's a high performance engine the power output always went down from the manufacturers figures, yet owners were adamant the engine ran better! It didn't and we proved it. Modern engine are designed to cope with differing grades of fuel, but putting say 99ron in a 1.2tsi will have this negative effect. The 1.2TSI actually runs best on 95ron. The ecu won't be able to fully compensate for much higher that usual octane rating (say 99ron) for that fuel. Higher octane fuels need longer to burn and this means advancing the ignition and fuel injection timing, amongst other things. Because the ignition won't be able to be advanced enough, the fuel will still be burning at BDC thus wasting some of that charge's power. It also means the exhaust gases will still be very hot and maybe still burning as it exits the exhaust port. Thus is causes more dirt/carbon on the valves and in the ports. It also can damage the cylinder head valves and seats. It's well documented in lots of technical online sites and has been known about for years and years. Not saying that if you put in some high octane because you can't get anything else that it will harm your motor. It won't, but running it on high octane unnecessarily long term most likely will. It also depends on how you drive the car as to how much harm could be done on high octane.  Below is a link to a not very technical article (it's easy to read for non technical types) and it's an article from the states showing different octane readings on the pumps but it's a completely valid article. If you want more technical stuff just google it...

 

http://www.whatcouldbegreener.com/142/fuel-octane-choosing-the-wrong-octane-will-cost-you/

There was a test done on TV once where they used a 'normal' everyday family car, a mid performance car and a high performance car and monitored the difference between normal octane and high octane fuels.

The normal car saw no difference or benefits but the higher the power output the better the difference, this backs up what Estate Man is saying, in a 110 bhp engine, the higher octane fuel will a placebo effect but you pays your money and you makes your choice.

[Ootohere]

At least Tesco bother to show results of testing while others do not bother to show anything on UK Super Unleaded 97 Octane minimum.

 

Best look at the results and figures, and consider emissions as well as MPG.

As to the 95 Ron Unleaded being the correct and recommended petrol as in post #15,  

actually in the UK that is the minimum octane to be used as i read it.  Maybe check owners manuals your selves.

http://www.tescopfs.com/our-fuels/tesco-momentum99

'emissions download'  & 'Millbrook report'

They are comparing to Tesco Unleaded (95 ron) bit then it is no different to other 95 ron fuels sold in the UK.

Some will be called Fuel Saver and the likes, but then Royal Dutch Shell and not telling you what makes the basic fuel a 'Fuel Saver', 

is it added detergents or what chemicals.

Edited 3 April, 2016 by GoneOffSKi

[Ootohere]

http://briskoda.net/forums/topic/390949-apr-release-the-12tsi-software-and-were-loving-it

AwesomeGTI were bigging up the Remap for the 1.2tsi, and the person doing the posts was taking the APR line on using 98 ron with the re-map.

As usual wrong since nobody shows in the UK the Unleaded as being 98 Super Unleaded.

So this is explained in the thread and it is 97 Octane Minimum Super Unleaded they use.    to Exceed 98 ron you need to look at Momentum 99 or Shell V-power Nitro+ in the UK, 

of Motorsport Fuels from the likes of Hyperflo, Gulf etc, 102 and higher octanes.

[vels]

Rick, I'm an ex-tech and engine designer. Using too higher octane is not recommended for any car not designed to run on it. High octane should only be used in higher performance vehicles. Most modern engine that are NOT designed to run on it won't benefit and it will in fact actually harm your fuel economy and performance. It also leads to higher soot content in the engine. I've dyn'oed many engine in my time as an engineer and unless it's a high performance engine the power output always went down from the manufacturers figures, yet owners were adamant the engine ran better! It didn't and we proved it. Modern engine are designed to cope with differing grades of fuel, but putting say 99ron in a 1.2tsi will have this negative effect. The 1.2TSI actually runs best on 95ron. The ecu won't be able to fully compensate for much higher that usual octane rating (say 99ron) for that fuel. Higher octane fuels need longer to burn and this means advancing the ignition and fuel injection timing, amongst other things. Because the ignition won't be able to be advanced enough, the fuel will still be burning at BDC thus wasting some of that charge's power. It also means the exhaust gases will still be very hot and maybe still burning as it exits the exhaust port. Thus is causes more dirt/carbon on the valves and in the ports. It also can damage the cylinder head valves and seats. It's well documented in lots of technical online sites and has been known about for years and years. Not saying that if you put in some high octane because you can't get anything else that it will harm your motor. It won't, but running it on high octane unnecessarily long term most likely will. It also depends on how you drive the car as to how much harm could be done on high octane.  Below is a link to a not very technical article (it's easy to read for non technical types) and it's an article from the states showing different octane readings on the pumps but it's a completely valid article. If you want more technical stuff just google it...

 

http://www.whatcouldbegreener.com/142/fuel-octane-choosing-the-wrong-octane-will-cost-you/

 

In most points I agree..

However, this would have been true just 5 years ago when most engines were non turbo charged.

Todays small engines deliver HP and torque figueres that most people would not have believed 10 years ago, meaning actually are high performance engines compared to ealier. Take the Ford 1.0 EcoBoost, its only rated for a lifespan of 250.000 km..

The compression ratio is high, intake air is hot. The fact that 95 RON can be run as recommended fuel is likely due to the cooling abillities of the direct ignition technoligy, providing cooler spark plugs preventing premature "ignition".

 

What we actually need, is some tech info on the ECU and what it can adjust to. My best guess is that the 1.2 TSI can manage 98/99 RON just fine, hence adjust timing to adjust for the slower burn. But it might take a first full tank for the ECU to adjust correctly.

 

Mine says "minimum 95 RON", and for models with that designation on the filler cap skoda has the following to say :

 

- Unleaded petrol that has a higher octane number than that required by the engine can be used without limitations.

 

■ On vehicles using prescribed unleaded petrol of min. 95 RON, the use of petrol with a higher octane number than 95 RON can increase the power and reduce fuel consumption

 

It also states for models rated 95 RON but can run on 91/92 RON  :

 

■ The use of petrol with an octane rating higher than 95 RON in does not result in either a noticeable increase in power nor lower fuel consumption in vehicles for which unleaded petrol 95/91, 92 or 93 RON is specified.

 

So there we have it..

 

But as mentioned before, it boils down to a personal preference and will be effected by both driving style and climate.

 

Just my 10 cents..

[Ootohere]

When i put 100 or 102 ron in my 1.4TSI rather than 99 ron the difference happens when the fuel starts reaching the engine.

(That is on a Stage 1 mapped car,  but without the use of the APR Switchable map function.)

 

Bum of the seat testing might be worth trying when going to 99 ron, or even 97 ron, 

after all it is just going to cost you an extra £2.25, or an Extra £4.50 if you think 2 tanks are needed to have any change.

(which it does not require.)

[Guest]

In most points I agree..

However, this would have been true just 5 years ago when most engines were non turbo charged.

Todays small engines deliver HP and torque figueres that most people would not have believed 10 years ago, meaning actually are high performance engines compared to ealier. Take the Ford 1.0 EcoBoost, its only rated for a lifespan of 250.000 km..

The compression ratio is high, intake air is hot. The fact that 95 RON can be run as recommended fuel is likely due to the cooling abillities of the direct ignition technoligy, providing cooler spark plugs preventing premature "ignition".

 

What we actually need, is some tech info on the ECU and what it can adjust to. My best guess is that the 1.2 TSI can manage 98/99 RON just fine, hence adjust timing to adjust for the slower burn. But it might take a first full tank for the ECU to adjust correctly.

 

Mine says "minimum 95 RON", and for models with that designation on the filler cap skoda has the following to say :

 

- Unleaded petrol that has a higher octane number than that required by the engine can be used without limitations.

 

■ On vehicles using prescribed unleaded petrol of min. 95 RON, the use of petrol with a higher octane number than 95 RON can increase the power and reduce fuel consumption

 

It also states for models rated 95 RON but can run on 91/92 RON  :

 

■ The use of petrol with an octane rating higher than 95 RON in does not result in either a noticeable increase in power nor lower fuel consumption in vehicles for which unleaded petrol 95/91, 92 or 93 RON is specified.

 

So there we have it..

 

But as mentioned before, it boils down to a personal preference and will be effected by both driving style and climate.

 

Just my 10 cents..

Vels, I'm not disagreeing with much of what you say but it depends on the motor concerned and what the designers intended. The last engine I was involved with on both design and development was an 800cc turbo charged 3 cylinder petrol engine. It was a relatively high performance direct injection petrol engine with a compression ratio of 11.1. It put out 100bhp DIN and 165nm at 1700rpm. It used several ground breaking features within and some great new materials for strength. We designed it to run on 95ron but it would take 97ron ok and was designed to do so. Above that, running 98+ron it became less efficient. It actually gave it's best power and torque on 95ron, again as we designed it. The trick is to get the electronics right so a powerful ecu is required to make the adjustments quickly and alter the parameters of the fuelling and ignition. The turbo was variable vane, variable nozzle and this operated at medium to high pressure much of the time to get the figures we needed. But the fact we designed it to run 95ron safely was the key to marketing the engine. It also helped lower emmisions.  Needless to say this engine was a specialist engine for a specific set of customers but it was an interesting project that is still ongoing I understand. 

[vels]

Vels, I'm not disagreeing with much of what you say but it depends on the motor concerned and what the designers intended. The last engine I was involved with on both design and development was an 800cc turbo charged 3 cylinder petrol engine. It was a relatively high performance direct injection petrol engine with a compression ratio of 11.1. It put out 100bhp DIN and 165nm at 1700rpm. It used several ground breaking features within and some great new materials for strength. We designed it to run on 95ron but it would take 97ron ok and was designed to do so. Above that, running 98+ron it became less efficient. It actually gave it's best power and torque on 95ron, again as we designed it. The trick is to get the electronics right so a powerful ecu is required to make the adjustments quickly and alter the parameters of the fuelling and ignition. The turbo was variable vane, variable nozzle and this operated at medium to high pressure much of the time to get the figures we needed. But the fact we designed it to run 95ron safely was the key to marketing the engine. It also helped lower emmisions.  Needless to say this engine was a specialist engine for a specific set of customers but it was an interesting project that is still ongoing I understand. 

 

Nice :-)  - must have been really fun to be part of.

Actaully I just tank 95 RON on the 1.2 TSI 110 HP. Tried a few tanks of V-Power, got slightly better milage but in terms of power I think the engine is somewhat boring so even if it should yield  a few HP more I dont really care.

Most of my driving is small country roads with cruise control at 80-85 km/h. With Shell FuelSave 95 RON I average my work driving around 19-20 km/l and combined average including city, mortorway and pulling a trailer is 17 km/l.

 

Some say the Fabia will be more fun to drive if the XDS+ is turned to max, but in standard setting it understeers in a degree that makes sporty driving hopeless.

 

It does the job , driving from A to B at a fairly low cost and okay comfort level - but thats about it.

So for me personally, I do not feel compelled to spending the extra money on fuel.

 

I'd rather spend the money on quality oil and I service the car for every 15.000 km instead of 30.000 km as the service book describes.

The stealer was not to happy about it, but did as told.

Edited 6 April, 2016 by vels

[scoobysn7x]

I've had a few performance cars a couple of T4's, a T5, and now the VRS, and I know from past experience especially with the T4's they ran really badly on 95 ron petrol, I once put a full tank of tesco unleaded in and drove down from glasgow and it ran like a bag of spanners awful hesitation really lumpy, thought there was issues, though about it realised the only thing I'd changed was the fuel, filled up with Vpower for the return journey and no running issues. I also found that for the same cost I would get better economy from the higher octane petrol (so if I put £20 of normal and £20 of super unleaded in the car, I would get more miles from the super) so for me its a no brainer. Even with my last car which was a remapped mondeo tdci it ran better on Vpower diesel, and again got better mpg from it, so I will always put super unleaded/diesel in my cars 

[Aredeth90]

Let me join in the discussion as well. By no means a scientist, but since i got my 110 tsi fabia last September i averaged 44-45 mpg mixed with a light-ish foot, all done on 95Ron from BP mostly.

 

Well, i got the V Shell 98 or 99, and the car felt exactly the same, my driving style was the same and yet i got 41-42 Mpg with it. Same for when i went to Belgium and had filled with 99 or 100 Ron, Mpg went down slightly, driving style the same, yet nothing noticeable in terms of power output.

 

All the above are feeling based only, using the same driving style, with next to no traffic (night to morning driving), mpg calculated from fill to fill and miles covered.

 

For me this was clear that i can spare the extra coins filling with 98+ Ron, as the car behaves the same, if not slightly worse in mpg terms.

 

Kind Regards