some calculations which shows 98 is better choice than 95

E95/98	km;	l/100km;	€/l;			l;	€;
E98	500	11	1,197		>	55,0	65,8
E95	500	11,5	1,157		>	57,5	66,5
E98	500	7	1,197		>	35,0	41,9
E95	500	7,5	1,157		>	37,5	43,4

Had a Seat Leon with the 1.4 TSi 140 PS for almost 4 years now. Its been fed on a diet of Tesco and Asda 95 RON petrol pretty much exclusively and runs fine. Has averaged 45 mpg. When I have been forced to use branded fuel (on holiday - no supermarkets close by) its run no better.

 

So when I get the Superb 1.4 TSi (hopefully next week) it will be run on a diet of Tesco and Asda 95 RON petrol.

 

It says 95 RON on the fuel flap and I much prefer to follow manufacturers advice. They do much more research than a few owners doing fill ups at various filling stations.

On 31/01/2016 at 03:14, Rainmaker said:

 

The RON definitely isn't marketing hype, in fact it's strictly legally controlled lol. You can raise and lower octane significantly simply with little tweaks (an additive, ethanol proportion etc) without even touching the base fuel. If it says 99 RON you can bet your bottom dollar it is. In fact due to the way fuel is distributed it may be even higher, as the fuel starts marginally higher than the labelling to account for the (slow) degradation in octane which naturally occurs over time in transit and storage.

 

There are variations in the way companies work, but it's the same end result. For example BP Ultimate is (was?) totally ethanol free, and the base fuel is specifically refined to 97 RON in and of itself. That's part of the reason it's so much more expensive (proportionally) to other fuels. Shell VPower is a more closely guarded commercial secret, but does contain some ethanol as well as other additives. Tesco M99 is actually made from cracked naphtha (a fraction different from petroleum). When you crack naphtha you end up with very high octane petroleum, to which Tesco (via the Greenergy petrol refinery they own) add significant levels of ethanol/methanol and oxygenates.

 

Various countries have differing traditional octanes (100, 98, 95, 91 etc) and oil companies obviously tailor their base fuels and blends to suit this. Likewise OEMs usually alter the ECU maps, timing etc to fit in. For example the Mazda 6 SkyActiv engine has 14:1 compression as sold in the UK market, based on our usage of 95 RON fuel. In the USA the same car is sold with the engine set up with 'only' 13:1 compression, to suit their standard 91 RON equivalent fuel.

 

Just because Shell sells fuel on both sides of the Atlantic, don't think it's all the same RON bar the 'marketing hype'. In fact you'd be paying a lot more at the pump in the US if you wanted 95 or 99 RON, rather than 91. Thus in Europe; same brand, different octanes (but the same detergent packages etc). Don't confuse branding (VPower) with the underlying product. For example even Coca Cola is totally different in the UK and USA, using sucrose in the UK and only corn syrup in the USA. Same name and packaging, totally different ingredients and taste. 

 

Keep in mind that in the US fuel is rated using AKI, not RON hence the lower apparent figure. So when you see 91 in the US it does not mean 91RON. 

39 minutes ago, skidpan said:

Had a Seat Leon with the 1.4 TSi 140 PS for almost 4 years now. Its been fed on a diet of Tesco and Asda 95 RON petrol pretty much exclusively and runs fine. Has averaged 45 mpg. When I have been forced to use branded fuel (on holiday - no supermarkets close by) its run no better.

 

So when I get the Superb 1.4 TSi (hopefully next week) it will be run on a diet of Tesco and Asda 95 RON petrol.

 

It says 95 RON on the fuel flap and I much prefer to follow manufacturers advice. They do much more research than a few owners doing fill ups at various filling stations.

 

Does the 1.4 TSI say '95 (min 91)' or 'minimum 95 RON'? There's a difference, and Skoda say that cars saying 'min 95' will perform better on 98+ but cars saying 95 (min 91) won't.

38 minutes ago, SC03OTT said:

 

Keep in mind that in the US fuel is rated using AKI, not RON hence the lower apparent figure. So when you see 91 in the US it does not mean 91RON. 

 

Yes I did remember that mate (I referred to it in one of my earlier posts). US 'regular gas' is 93 RON (89 AKI/PON) hence Mazda detuning SkyActiv engines for the US market, and their V-Power Nitro+ is 98 RON (93 AKI/PON). 

2 hours ago, Rainmaker said:

 

Does the 1.4 TSI say '95 (min 91)' or 'minimum 95 RON'? There's a difference, and Skoda say that cars saying 'min 95' will perform better on 98+ but cars saying 95 (min 91) won't.

 

My Leon say 95 min and that is exactly what I have always fed it. The car runs absolutely perfectly in all conditions but I suppose in a lab at max rpm/load it may run better on 98 RON. But since I drive in the real world rarely exceeding 4000 rpm or more than 1/2 throttle any benefits that 98 RON may have would never be spotted.

35 minutes ago, skidpan said:

 

My Leon say 95 min and that is exactly what I have always fed it. The car runs absolutely perfectly in all conditions but I suppose in a lab at max rpm/load it may run better on 98 RON. But since I drive in the real world rarely exceeding 4000 rpm or more than 1/2 throttle any benefits that 98 RON may have would never be spotted.

 

The benefits of higher octane go further than that mate. For example it'll allow the engine to run at lower rpm for a given road speed, i.e. allowing gears to change up earlier than a lower octane fuel. Around town on 99 RON I will often see the car cruising along at just over 1,000rpm. On 95 the revs were invariably closer to 1,500rpm in the next gear down when driving along the same roads at the same speeds. This is all due to ignition advance, but of course everyone is free to learn the differences and make their own choices.  

2 minutes ago, Rainmaker said:

 

The benefits of higher octane go further than that mate. For example it'll allow the engine to run at lower rpm for a given road speed, i.e. allowing gears to change up earlier than a lower octane fuel. Around town on 99 RON I will often see the car cruising along at just over 1,000rpm. On 95 the revs were invariably closer to 1,500rpm in the next gear down when driving along the same roads at the same speeds. This is all due to ignition advance, but of course everyone is free to learn the differences and make their own choices.  

 

No it won't. The gear ratios are fixed. If the revs vary the clutch is slipping.

 

My cars are manuals and always will be, I decide when to change not some idiot back in Germany.

1 hour ago, skidpan said:

 

No it won't. The gear ratios are fixed. If the revs vary the clutch is slipping.

 

My cars are manuals and always will be, I decide when to change not some idiot back in Germany.

 

So we've gone from the guys making the engine know best and preferring to follow their advice on fuel, to preferring to ignore the idiots in Germany. Please note I said nothing about clutch slip or varying revs, I said higher octane allows you to choose the next gear up for any given road speed. This applies equally to manuals or DSG. I'm glad you can choose to only drive manual, it's my preference too. Unfortunately my wife broke her back and can't use her left leg so DSG it is. 

 

Ok mate, have a nice afternoon. 

Edited 21 February, 20179 yr by Rainmaker

Isn't this more about the energy that comes from the higher rating fuel?  As the torque will be greater due to greater calorific value and therefore the required necessary force will be produced at a lower RPM.

 

@skidpan You are likely calibrated for your manual car and the rev per mph for cruising with your current fuel choice etc but if you can get more force "torque" from a different fuel then the required revs will be lower for that speed or you could drive at the same revs and get a higher speed.

 

1 minute ago, Bud said:

 

@skidpan You are likely calibrated for your manual car and the rev per mph for cruising with your current fuel choice etc but if you can get more force "torque" from a different fuel then the required revs will be lower for that speed or you could drive at the same revs and get a higher speed.

 

 

On a manual the relationship between revs and speed is fixed. No fancy petrol can change that. On a manual if the revs vary at a given road speed either the clutch is knackered or the wheels are spinning.

 

On my Leon its 2500 rpm at a true 70 mph regardless of the day of the week, wind direction or any other factor you can think of.

 

On auto revs go up and down like a brides knightdress with a twitch of your right big toe. Very different to a manual and one of the many reasons I hate auto's.

@Bud Almost mate. Higher octane fuel often will actually have a slightly lower calorific density than 95 RON. However, the extra ignition advance possible in TSI and similar engines on higher RON fuel negates this fact, and usually leads to better MPG overall. 

 

You're correct about the extra power low down though and as such you will get better speed per rpm and the ability to use higher gears without the engine lugging. For example where you'd only be able to use 3rd at 27mph or 4th at 38mph, high octane would allow the use of 4th and 5th instead. Again this helps save fuel. 

3 minutes ago, skidpan said:

 

On a manual the relationship between revs and speed is fixed. No fancy petrol can change that. On a manual if the revs vary at a given road speed either the clutch is knackered or the wheels are spinning.

 

On my Leon its 2500 rpm at a true 70 mph regardless of the day of the week, wind direction or any other factor you can think of.

 

On auto revs go up and down like a brides knightdress with a twitch of your right big toe. Very different to a manual and one of the many reasons I hate auto's.

 

That doesn't change the fact you can change up earlier without lugging and produce more torque low down though, does it?... 

I change gear at appropriate times. Been driving long enough to tell when a change is needed without a rev counter or a DSG box.

 

But the quoted BHP and torque figures are at wide open throttle, who drives like that. In real world conditions we use a fraction of the available power/torque so that extra 2 or 3 (perhaps) is irrelevant. At 70 mph in a "normal" car it takes about 30 bhp on a level road, possibly less. That means that at 2500 rpm I have at least 57 BHP's spare of the 87 bhp's that is theoretically available at that engine speed.

31 minutes ago, skidpan said:

I change gear at appropriate times. Been driving long enough to tell when a change is needed without a rev counter or a DSG box.

 

But the quoted BHP and torque figures are at wide open throttle, who drives like that. In real world conditions we use a fraction of the available power/torque so that extra 2 or 3 (perhaps) is irrelevant. At 70 mph in a "normal" car it takes about 30 bhp on a level road, possibly less. That means that at 2500 rpm I have at least 57 BHP's spare of the 87 bhp's that is theoretically available at that engine speed.

 

You keep on doing that; introducing completely new and irrelevant information to confuse the original point. It's called a strawman, in case you'd never heard of it before. You might only pootle around the place, but not everyone does so please don't confuse your own motoring habits with those of everyone else. I definitely do make full use of the rev range and power band, and my car sees the red line every single journey once the oil is warm. No point paying for the higher powered model to short shift and treat it like a diesel all the time, is there? The tachometer isn't necessary, no, but it's handy especially when you are dropping three or four gears to obtain brisk acceleration during a limit change or prior to an overtake on an NSL road, for example. If you can tell the difference between ~4,000rpm and ~5,500rpm (i.e. approaching red line) just by sound then all power to you, but for those of us wringing out the horses it's handy to know at a glance where the power is. Since you rarely go over 4,000rpm anyway (in your own words) then you'd likely not notice the difference, but again we can't infer other people's behaviours using our own habits (nor for that matter infer the top end behaviour of an engine 600cc larger and twice the power of our own, when we only use half of our own engine to begin with).

 

You're fully entitled to use supermarket 95 RON and all power to you. I'm not paying for your fuel nor your car, so I don't give two hoots either way. I'm simply saying you're mistaken in the belief that higher octane isn't beneficial, and you've gone from saying you prefer to 'follow the manufacturer's instructions' to finding out that in actual fact the manufacturer recommends 98+ for maximum power and economy, and therefore deciding that nobody would benefit anyway so we shouldn't listen to the 'idiot in Germany' after all...  

29 minutes ago, skidpan said:

I change gear at appropriate times. Been driving long enough to tell when a change is needed without a rev counter or a DSG box.

 

But the quoted BHP and torque figures are at wide open throttle, who drives like that. In real world conditions we use a fraction of the available power/torque so that extra 2 or 3 (perhaps) is irrelevant. At 70 mph in a "normal" car it takes about 30 bhp on a level road, possibly less. That means that at 2500 rpm I have at least 57 BHP's spare of the 87 bhp's that is theoretically available at that engine speed.

Are you really changing at the most efficient point or just what you feel your experience supports.

 

BHP at WOT and with what fuel?

 

All the torque and power curves are entirely dependent upon the fuel.

 

At the end of the day if you are content running a car on paraffin, methylated spirit, diesel or LPG they will all have different characteristics with different torque and power curves.  You appear happy to use the fuel you have selected so be, people also used to be happy with 4 speed gearboxes! 

 

I would also suggest that the designers do know what fuel is best.

Pointless continuing.

 

If I drove to the red line on every trip I would only be wasting fuel and getting Argos points by the dozen.

 

You drive how you want, I will drive how I want as well.

 

Main difference is I have a cabinet full of trophies from my racing days and bar room talk does not win those. And I used 95 RON petrol.

No UK Filling stations sell 98 ron Super at the pumps currently so you just have to go with 97 ron minimum or 99 ron minimum.

http://volkswagen.co.uk/need-help/owners/Fuel

 

& not just VW GTI / R engines, 

ones used in Skoda, SEAT & Audi like the Euro 5 emission 1.4 TSI 132-136 kW Twinchargers. (177-185 bhp)

Edited 21 February, 20179 yr by Awayoffski

10 minutes ago, skidpan said:

Pointless continuing.

 

If I drove to the red line on every trip I would only be wasting fuel and getting Argos points by the dozen.

 

You drive how you want, I will drive how I want as well.

 

Main difference is I have a cabinet full of trophies from my racing days and bar room talk does not win those. And I used 95 RON petrol.

 

Why would I care about MPG? I'm driving a 2.0 TSI because I like to drive, not because I want to save fuel. Mid to late 30s around town and early to mid 40s on the motorway is more than fine by me. My next car is rated at 15mpg, see if I care when I'm driving it across the Moors.

 

Again with the pointless references. What do racing trophies have to do with what fuel the engine a TSI engine is designed for? Unless of course you were racing in a TSI engine on 95 RON fuel? In which case yes it's relevant (kind of). But as you know, the better racecraft and better driver doesn't necessarily have to be in the fastest or most optimised car to win a race. I digress. If we're comparing credentials I'm a RoSPA Gold and training for entry into the HPC, but that's about as much relevance to the discussion than what size shoes my daughter wears.   It's just pointless willy waving that has nothing to do with the topic at hand. It's called Appeal To Authority, trying to win an argument by asserting your (unrelated as it happens) superiority.

 

Skoda (the 'manufacturer we should listen to', in your words) say 98+ RON is best for these engines. You can choose to follow that or not. Who cares? That's about all there is to it either way.

Edited 21 February, 20179 yr by Rainmaker

1 hour ago, Rainmaker said:

Skoda say 98+ RON is best for these engines. You can choose to follow that or not. Who cares? That's about all there is to it either way.

 

I will post next Wednesday when I get the car but if the fuel flap says the same as the brochure I have in front of me then its Min 95 RON or Min 91 RON. No mention of 98 RON at all. But it does say that using low octane fuel (presumably the 91 RON) will affect engine performance. Irrelevant in the UK since 95 RON is as low as it goes.

What vehicle are you talking about having an owners manual for, and is this some car you have yet to get?

 

?

Any reason you are debating the benefit of the Prescribed fuels for a Mk3 Skoda Superb by discussing the Prescribed or recommended fuels for a 

1.4tsi 140ps SEAT?

 

All Euro 5 Emission & Euro 6 Emission EU Official Emissions testing is done with 95 octane fuel inside those temperature controlled buildings.

That is not saying that lower emissions can not be acheived and more efficient running out in the real world with a higher octane, 

even at less than half the maximum hp / torque.

http://skoda.co.uk/pages/fuel-consumption-statement.aspx

Edited 21 February, 20179 yr by Awayoffski

Oh deary me i think ill stick with my diesel

LOL

Will you fill with Diesel or Premium Diesel though, and do you benefit in any way with more efficient running with a higher cetane and possibly detergents.

No comment im not swinging my handbag in this one....... 

Thanks all the same

11 minutes ago, Awayoffski said:

What vehicle are you talking about having an owners manual for, and is this some car you have yet to get?

 

?

Any reason you are debating the benefit of the Prescribed fuels for a Mk3 Skoda Superb by discussing the Prescribed or recommended fuels for a 

1.4tsi 140ps SEAT?

 

Don't have a manual, have a brochure. Superb 1.4 TSi 150 PS arrives next Wednesday to replace the Leon 1.4 TSI 140 PS have have owned and run for almost 4 years on 95 RON petrol.

 

If the fuel flap says 98 RON then I will have to search our some fuel but if as expected (reading the brochure) its 95 RON then its business as usual.