Super Unleaded provides zero benefits for stock TSI engines

[Orville]

Some may disagree, but after one year of ownership including 20x tanks of Premium Unleaded and 10x of Super I have come to the conclusion that Super is a complete waste of money for a stock VRS TSI. I have recorded zero performance or fuel economy differences between them.

 

*Average fuel economy for 20x tanks Premium Unleaded = 27.17mpg

*Average fuel economy for 10x tanks Super Unleaded = 26.46mpg

 

Results: (measured using tank to brim method, Green = Premium, Red= Super)

 

 

..and a pretty graph showing mpg per tank and combined mpg over the period.

 

Edited 9 March, 2015 by Orville

[andyvee]

Only 1 flaw in your logic - it takes the ECU quite some time to adjust fuel trims and ignition timing to the optimum settings across the full load and rev range - I would expect at least half a tank of fuel from my experiences of resetting all fuel trims on ECUs and observing long and short term fuel trims when doing LPG conversions.

 

You would need to run at least 3 consecutive tanks of each fuel to get a true picture, I am not doubting your results as the differences would be small anyway.

[Dempsek]

No surprise for me.

 

I think it was the AA that said the advantage super fuel has is better cleaners.

[Redboy]

It looks like your car never leaves urban areas if your MPG is always below 30 MPG. Would that also be a factor?

[Richf]

Only 1 flaw in your logic - it takes the ECU quite some time to adjust fuel trims and ignition timing to the optimum settings across the full load and rev range - I would expect at least half a tank of fuel from my experiences of resetting all fuel trims on ECUs and observing long and short term fuel trims when doing LPG conversions.

You would need to run at least 3 consecutive tanks of each fuel to get a true picture, I am not doubting your results as the differences would be small anyway.

No it doesn't , if the fuel grade isn't suitable the ecu picks it immediately

Op how have you measured the difference in performance?

[neiln]

I've not noticed any difference in feel, but unless it was a big difference I suspect it would only show on the limit of performance anyway.  I have only used 95ron  a couple of times (when I've needed fuel and can't find super) so can't be clear if that was the cause, but I did get slightly lower mpg on those tanks.  It wasn't enough of a difference to cover the extra cost that Shell charge for super unleaded nitrovpowerplusquantumhyperspeedgoldplatedgogojuice (or whater they call it) though, more like about half the diffrenence.  I have however found a local independent garage that has, what they claim to be, 98RON, at only 3 or 4 pence more a litre than the 95RON.  So I've started doing half a tank of Shell nitrovpowerplusquantumhyperspeedgoldplatedbl00dyexpensivegogojuice, for every tank and a half of the local independent 98ron.  I believe the detergents in the premium fuel may make a difference over time, and from what I read, they are at 'clean up dose' so a tank full every 4 is all you need.

I could be wasting my money, foolishly swallowing what the motoring press and fuel manufacturers put out.  There's no way to know, unless you run an extended test over many years on a large fleet.

Still, at least oil is cheap currently and, I read, not about to go up in price for a wee while.

 

Looking at your data Orville, it looks like your mpg was slowly improving from new through to September, then stabilized.  I take it the engine was running in, which could have caused as much difference from tank to tank as fuel type perhaps.  If you carry on with the recordings, I reckon you'll see a small improvement as the weather warms up again.  I noticed a worsening of mpg when it got cool last October and November at least, so I hope it reverses as it warms again.  It might be worth trying a stint or two of 2 or 3 consequitive tanks of super again in the summer, to confirm your findings or not.

[andyvee]

No it doesn't , if the fuel grade isn't suitable the ecu picks it immediately

Op how have you measured the difference in performance?

I'm not talking about incorrect fuel.

 

If you observe long term fuel trims they take some time to adjust to absolute optimum, as well as factors such as ignition advance. The car will quickly get close to the optimum, but most ECUs for safety reasons will then take a while to lean off further or advance the ignition further.

 

I can only go with my experience of switching between LPG and petrol when on rolling road sessions, in order to optimise the LPG map to be as close as possible to the petrol map so that when you switch between fuels the fuel trims etc. don't go wild.

 

After a long time running on LPG only you will see the ignition advance way beyond what is suitable for petrol - as soon as you switch back the knock sensor kicks in and retards the ignition instantly. If you only run for a short period on LPG you don't see the same effect. 

 

I am talking absolute extremes here, but if you want to run a true comparison you need to run 2 or 3 tanks of Fuel A, then 2 or 3 tanks of Fuel B, then repeat.

[Orville]

The surge in mpg during the summer was due to me taking the kids on days out / long-range trips during their holidays. The fall during the winter months is due to the kids refusing to walk to school in the cold and wet weather. Terrible mpg during the first few tankfulls was just me seeing what the car could do, in amongst one long Easter trip. Most of my mileage is London Town driving, hence low overall mpg.

[Orville]

Op how have you measured the difference in performance?

Only with my bum. With my old Subaru's you could feel the difference within 20miles of swapping between Premium and Super but with the Octy there is no noticeable difference. I do not believe the TSI engines in stock form work off the knock sensor, so see little or no gains from higher octane fuel.

[Orville]

It looks like your car never leaves urban areas if your MPG is always below 30 MPG. Would that also be a factor?

90% correct. The car gets driven (relatively hard) around town, with only the occasional family trip to bump up the mpg. On the rare occasion I take her on the motorway she'll do late 30's at 70-and-a-bit. Edited 9 March, 2015 by Orville

[neiln]

you're doing lots of short journeys aren't you?  that's my guess anyway, as even driving right through central london I'll get 28 to 32ish mpg so long as I've done 12 or so miles or more.  I guess with that sort of driving you would be unlikely to see a difference.

[neiln]

as a comparison.  I filled mine with the Shell nitrovpowerplusquantumhyperspeedgoldplatedbl00dyexpensivegogojuice at staples corner last friday evening, about 9pm, then drove M1, M6, M54 (70 to 75 mainly) and A41 to Chester (in [cough] fun mode [/cough].  maxidot (which I find fairly accurate) read 38.something mpg for the trip.  Sunday a short run to tesco and b and q, about 4 miles, oil temp didn't even register until on the way home, driven sedately in [cough] fiancee speed controlled mode [/cough] that trip registered 26 mpg.  Left chester about 10pm, a51 (some in fun mode), m6, m1 at about 70 to 75, and right through an empty london via marble arch, hyde parkk corner, brixton and on to near crystal palace in fuel conservation mode.  range read zero about 2 miles from home but I got 400 miles from the tank, maxidot reading 38mpg since refuel.

[Richf]

Bum dyno's are rarely calibrated!

As for the difference between running lpg and petrol that's a useless comparison due to the wildly different energy content between the fuels

The car doesn't know what's in the tank , it doesn't know what you put in last time it ONLY knows whether there is knock or not and will advance to the maximum value on the map provided there is no knock , if there is knock it will interpolate between this maximum figure and a lower safer map , this results in the reduction in performance.

If you don't drive in a way that loads the engine to the point where it would potentially knock there is no benefit from running higher octane fuel

It's entirely possible that cooler temperatures etc would help to prevent knock under certain conditions so you may not be experiencing any loss of performance , but under different circumstances ie prolonged hard driving , you might

[Bindinbear]

Read this with interest. Slightly off topic is it recommended that you use 97/98 RON fuel all the time in the TSI? I notice the filler cap says 95 RON.

My old golf 2.0 TFSI I was told the good stuff always as it damages the injectors otherwise??

I have had my car literally a week from new and i am running it in despite being told its unnecessary as i want the car to be tip top and give it a fighting chance. I've even considered an unscheduled oil change at 1000 miles!! (Bit anal i know) My daily commute is 18 mile round trip, stop start town work. I'm finding it doing around 26mpg. Guessing it will improve with time.

It does seem to be drinking the fuel, despite light acceleration and hasn't seen 40 +mph yet but then again it is a DSG.

[Gerrycan]

I'll just talk in Octanes.

Here in Australia the standard ULP runs at 91 Octane, then there is the 95 Octane recommended by Skoda as the minimum for my 1.4tsi(103kw)and 98 Octane which many in the Aus forums swear by.

I ran on 95 Octane for several tanks from new and due to the fact that there are a lot of dead flat roads out of Adelaide where I live, I was able to get a good idea of the fuel consumption at steady cruise of 110kph (true not speedo indicated) was 5.7l/100 (ambient temperature 20deg C and zero wind no A/C).

I experience throttle hesitation and jerkiness when the engine is cold and it was recommended that I should run 98 Octane to see if it cleared the problem which I did for several tanks.

Consumption on the 98 octane at steady cruise for the same conditions was absolutely identical and no discernible difference in overall average consumption.

I'll be honest, I did not expect any consumption improvement and it confirmed many independent tests that there is no gain in using a higher octane unless the car is designed to do so.

As far as the better detergents used in the highest octanes are concerned I don't know, but as my car is direct injection I would not expect any improvements as it has no opportunity to spray on the carbon build up that occurs on the intake manifold and valve stems. Of course this would not be true for vRS petrol and any other engine which have manifold AND direct injection banks.

My cold running hesitation issues have not changed, but it is a transient issue for the first kilometre or so only, but a pain in the posterior for the initial 100 metres of 1st gear.

It is worth mentioning that there are other fuels available here with the same nominal Octanes but with varying percentages of Ethanol added.

Some locally produced cars are designed to run on it but the general recommendation (and from Skoda) is steer well clear of it.

I have since switched back to 95 Octane and fuel consumption has remained consistent.

Edited 10 March, 2015 by Gerrycan

[neiln]

Nothing anal about wanting to look after your car, or what you propose.  Mine got fresh oil at 2k.

 Manual says, for the vrs at least, 95 is fine but you may notice better performance from higher octane.

[Mikek3111]

Be interested in this thread. I don't have a vRS but have an FSI. Fuel flap says super unleaded only and owners manual says 97/98 but can run 95 but with lower performance (it's a 1.6 it has no performance )

Reason I'd like to know is my local petrol station is a BP which only has 1 pump that sells BP Ultimate and there's always queues for it. I've been tempted to put standard 95 in it as the prices on the ultimate are slowing creeping up and up again, plus the fact that the other pumps are always empty. Tbh I've used Shell supermaxnitrothingymebob and tesco momentum and haven't really seen much difference between them two, only really maybe 1mpg.

Obviously being a 10 year old car now things are going to get dirty and fragile but could it really do any harm?

I'd much rather have the extra few quid in my pocket but not if its gonna damage the car.

If the only real difference between the two is the additives/cleaners would it not suffice just to use 95 and chuck a bottle of wynns injector cleaner in it every 3-4 tank fulls?

Edited 10 March, 2015 by Mikek3111

[Gerrycan]

Be interested in this thread. I don't have a vRS but have an FSI. Fuel flap says super unleaded only and owners manual says 97/98 but can run 95 but with lower performance (it's a 1.6 it has no performance )

I'd stick with the manufacturer's recommendation of 97/98 octane and because your car is not direct injection the 'superior' detergents should be keeping it clean anyway so little point in using Wynn's.

[hobbie2k]

It is worth mentioning that there are other fuels available here with the same nominal Octanes but with varying percentages of Ethanol added.

Some locally produced cars are designed to run on it but the general recommendation (and from Skoda) is steer well clear of it.

I have since switched back to 95 Octane and fuel consumption has remained consistent.

Did you get a reason to stay away from it?

In Minnesota (where I'm from originally), all road legal petrols must have at least 10% ethanol and I'm not aware of any significant issues arising from its use. Our 2.0T Jetta ran just fine, and my parents' SR20DE Nissan has been running on it for 250k miles without a single fuel issue.

I tried e10 here a couple times in my SR20 Pulsar and my Cressida and the only thing I noticed was a small drop in the number of kms I get from a tank, but it was by no means a controlled test.

Edited 10 March, 2015 by hobbie2k

[Gabbo]

In europe all petrol is e10 I believe.

However, in some parts of europe you can buy higher concentrations of ethanol like e70.

 

Some manufacturers offer a "flexi-fuel" engine which is able to automatically detect the ethanol concentration & adjust the spark & injection timing according.

 

Engines which are not adapted to run higher ethanol concentrations won't run very well with it.

[Bindinbear]

Might keep using ultimate/ nitro petrol till shes run in then every other tank mainly due to the extra cost as others have said.

Some of the running in thing comes from my lack of trust in vag group engines tbh. I had a 9n3 gti polo from new, ran that in and it had timing chain issues and all sorts! My wifes current 1.4 se polo with 9k from new is having an engine rebuild as i type!! :-(

Edited 10 March, 2015 by Bindinbear

[butchvrs]

I have run Shell V-Power for years, firstly in a Sapphire Cosworth 4x4, then for the last 11 my mk1 Vrs, and my new car (TSI Vrs) will be treated the same.

 

I have found that they respond better (performance wise), run smoother and in certain circumstances give slightly better consumption.

But that's just running on V-Power and nothing else.

One thing I do not do under any circumstance is use Supermarket fuel! 

 

I think there's nothing wrong with being "anal" about your servicing, especially if it's your car and not Company, and if you intend to keep it.

 

The previous two cars mentioned above got an oil and filter every 5000 miles, both were well over 100,000 miles when I sold them and still on their original turbo's etc and I never had any engine issues with either.

Look after them and they'll look after you.

[BigLee]

95 for mine when it lands and an oil change when it needs it, no use in babying them too much

I`ve found forums can bring out the most anal people lol!  

Oil, fuel and running in are the most discussed

[kallekilponen]

In europe all petrol is e10 I believe.

However, in some parts of europe you can buy higher concentrations of ethanol like e70.

 

Some manufacturers offer a "flexi-fuel" engine which is able to automatically detect the ethanol concentration & adjust the spark & injection timing according.

 

Engines which are not adapted to run higher ethanol concentrations won't run very well with it.

Here in Finland all 95 RON is 95E10, so it contains 10 % ethanol.

 

And all 98 RON is 98E5, so it contains 5% ethanol. (So does the 99 RON Shell V-Power, which is basically 98E5 with some addatives.)

 

They also sell E85 and RE85 on some petrol stations, which contains 85% ethanol (or recycled bio-ethanol as indicated by the RE).

 

 

But that's just running on V-Power and nothing else.

One thing I do not do under any circumstance is use Supermarket fuel! 

I've been quite adamant on that myself as well. Though I'd never put V-Power in my car either, way too dirty with all those additives. According to every independent test I've read, Neste sells the cleanest petrol here in Finland (and they sell it to pretty much every other chain as well, who just add their own additives that in reality just make your engine dirtier.) So every single tank of petrol I've filled in our Volvo has been 98E from Neste.

 

(In the latest test I read they used 280 liters of petrol on a Mercedes-Benz M102.982 engine in a test rig in controlled conditions and measured the soot collected in the valves during that time. The results for the major chains were: Neste 2g, Esso 3g, SEO/St1/Teboil 4g, Shell 6g.)

Edited 10 March, 2015 by kallekilponen

[racman]

 normal u/l for road use is all you need