I've just noticed, when finding out the pressures that should go in my tyres, that I'm supposed to fill my 1.4TSI with Super.

I'm sure I will get more power and better mpg but has anyone done back to back tests on the relative merits of "Full fat" against "skimmed"? Do we think it works out the same price per mile?

Its quite a lot more expensive and not always available.....

Dill

Its tricky to test back-to-back as an ordinary punter, because the ECU adapts to how potent the fuel is.

So if you've always filled up with 95 RON unleaded, then switched to 99 RON super unleaded, it'd take a while before the 99 RON had any effect - possibly even until the next fill-up.

A few of the car magazines, and Top Gear have done tests where they completely drained the tank and reset the ECU. It wouldn't have been on the same engine but the conclusion was that yes, there is a slight performance improvement running the super unleaded.

If I find a link to the article, I'll post it.

Probably find that the bigger the engine is the better the mpg difference will be.

I seem to remember the improvements from super unleaded only materialised with more 'performance' orientated cars i.e. Scoobys etc. I seem to remember there was no improvement seen with smaller less powerful engines.

I've just noticed, when finding out the pressures that should go in my tyres, that I'm supposed to fill my 1.4TSI with Super.

I'm sure I will get more power and better mpg but has anyone done back to back tests on the relative merits of "Full fat" against "skimmed"? Do we think it works out the same price per mile?

Its quite a lot more expensive and not always available.....

Dill

I've tried both on my 1.8TSI and can't tell any difference. Surprised your 1.4TSI is labelled for super - my 1.8TSI is clearly labelled for ordinary 95 octane (or 91 in an emergency).

John

This Fifth Gear review shows the difference between supermarket unleaded, Shell Optimax and BP Ultimate in three different cars, a Clio, VW Golf GTI and a Subura Impreza.

It focuses more on performance than economy, but then if a particular fuel makes a particular car go faster, then the same engine shouldn't need as much of the fuel to go at ordinary speed (in theory).

I agree with Jrayworth, my 1,8TSi states 95 octane for normal use, 91 in emergency.

As far as I can see unless your car is "tuned up" or a super-sports car then stick to the bog standard 95 octane stuff, it's cheaper. One point to make and that's on the EU mainland our unleaded is sometimes known as Super.

I have tried shell v power diesel on the octy vrs and not really any difference i found,certainly was not worth the £1.24 a litre price.you better off going to halfords or some auto shop and buying a bottle of millers petrol power,it comes in 500ml bottles and you use 50 ml per fill up,so it lasts longer and it does appear to make a difference,i used to use it when i had the scoob and it gave me better performance smoother through the rev range, plus it cleans your injectors.Haven't tried it on the vrs yet but keep meaning to go buy a bottle.

Edited 3 July, 201015 yr by Dolla

Crikey, yes you're quite right. It clearly says Super, but also 95 Octane. If Super in GB is 98, we're in the clear.

panic over.

dill

Crikey, yes you're quite right. It clearly says Super, but also 95 Octane. If Super in GB is 98, we're in the clear.

panic over.

dill

Most of Europe classes Super as 95 octane IIRC... That could be the reason

The ordinary stuff abroad is 91 octane, super 95 and super + 98+

i put v power in me ahem wrx and oh my god chalk and cheese ran far better on v power i got 7 more miles to the gallon as well and it made it so responsive it was great . but put bp ultima diesel in me wifes tdipd polo and never noticed any change was still cheaper than fuel up in orkney which is £ 1.31 :'( :'(

It will only have an effect if the car is able to adjust its ignition timing

Most cars have a 'knock' sensor to retard timing when detonation occurs, but if the car has an 'active' knock sensor which allows it to wind timing on to the point just before det, then the car will see a performance benefit from higher octane fuel as the timing will be optimised

The VRS engine has the ability to do this

Not many bog standard cars do, and certainly not any non boosted ( normally aspirated ) engines do that i've come across

Remember Octane isnt a measure of how 'potent' a fuel is, Octane rating ( RON and more importantly MON ) is just a measure of a fuels resistance to detonation, therfore to take advantage of a fuel with a higher RON/MON ( Research Octane Number/Motor Octane Number ) a car needs to have its ignition timing/Compression ratio optimised for the fuel, either by a switchable map for hi-low octane or by having an 'active' knock sensor as describe above

Edited 5 July, 201015 yr by VRsMatt32

IMHO there is a noticeable difference between Supermarket 95 RON and super unleaded.

I've found that the difference is much less between 'good' fuels i.e. Shell 95 Ron and super unleaded.

If I had a Shell nearby I'd run the car on standard unleaded but because I've only got supermarket fuels I always use SU.

IMHO there is a noticeable difference between Supermarket 95 RON and super unleaded.

I've found that the difference is much less between 'good' fuels i.e. Shell 95 Ron and super unleaded.

If I had a Shell nearby I'd run the car on standard unleaded but because I've only got supermarket fuels I always use SU.

Thats a different issue, supermarket fuels are rubbish

They come from the same tanker as branded fuel in most cases and have the same nominal RON/MON ratings, however at delivery the delivery driver will mix certain additives into it depending on where they deliver, the branded fuels are generally much better.

I have to say I ran my s2000 on Vpower of Tesco 99 when I had a few mods done to it and it used to run far better than on 95!

Since having the octy remapped iv still only ever ran it on 95 and its still ballistic! I may try a couple of tanks of 99 to see if i can tell the difference or not!

Anyone with a remapped TSI vRS done any tests? Opinons?

I have to say I ran my s2000 on Vpower of Tesco 99 when I had a few mods done to it and it used to run far better than on 95!

Since having the octy remapped iv still only ever ran it on 95 and its still ballistic! I may try a couple of tanks of 99 to see if i can tell the difference or not!

Anyone with a remapped TSI vRS done any tests? Opinons?

Tesco 99 is pretty good in terms of power, it has a strong RON and it doesnt degrade like Optimax does over time so you wont get a 'stale' tank like you can with some other fuels

I still wouldnt use a car long term soley on supermarket fuel tho................unless it was the wifes lol!

Tesco 99 is pretty good in terms of power, it has a strong RON and it doesnt degrade like Optimax does over time so you wont get a 'stale' tank like you can with some other fuels

I still wouldnt use a car long term soley on supermarket fuel tho................unless it was the wifes lol!

No it's my car haha and I don't use standard supermarket fuels, lucky for me there's a Shell garage right next to me and its only 113.9p per litre, so I always use that for 95

And I say only 113.9 still disgraceful!

In all independent tests between supermarket vs branded fuels that I have seen so far there is always a MAX difference of 4% in the power difference, most of the times with a difference near to 0% depending on the car tested. As reference, "normal" cars 0%, "agile" cars (up to 200 Bhp) around 2/3% and "high power" cars (more than 200 bhp) around 3/4%

Bear in mind that this does not translate necessarly to fuel economy, but in this case let´s imagine that this means that they use 4% less fuel.

Check your local gas stations if the difference between supermarket vs branded fuels is lower or higher than 4%. If there is a higher difference there is no reason to use the branded one, if the difference is lower you can think about using them.

My personal opinion is that if your car says that it works well with 91RON, don´t use higher, if it says it runs with 95 RON don´t use higher, and only if it specifically says that 98/99 RON are needed then u should go for it. Otherwise it is just a drain to your pocket in favor of the oil companies.

Of course never use fuel with lower RON than the recommended one unless absolutely necessary.

In all independent tests between supermarket vs branded fuels that I have seen so far there is always a MAX difference of 4% in the power difference, most of the times with a difference near to 0% depending on the car tested. As reference, "normal" cars 0%, "agile" cars (up to 200 Bhp) around 2/3% and "high power" cars (more than 200 bhp) around 3/4%

Bear in mind that this does not translate necessarly to fuel economy, but in this case let´s imagine that this means that they use 4% less fuel.

Check your local gas stations if the difference between supermarket vs branded fuels is lower or higher than 4%. If there is a higher difference there is no reason to use the branded one, if the difference is lower you can think about using them.

My personal opinion is that if your car says that it works well with 91RON, don´t use higher, if it says it runs with 95 RON don´t use higher, and only if it specifically says that 98/99 RON are needed then u should go for it. Otherwise it is just a drain to your pocket in favor of the oil companies.

Of course never use fuel with lower RON than the recommended one unless absolutely necessary.

And avoid those stupid "power boosting" fuel additives too, theres a couple of tests, one on fifth gear on you tube - they tested about 5 different products benchmarked in an engine just running on standard 95 RON fuel and all of them actually lost power!

Mind you they were using a rover K - series engine to do the tests :no:

ive read page after page after page on this topic and my advice is just try it yourself , but run it for 3-4 tankfuls and see what you think.

ive always found my cars have ran better on SUL, not always faster but most definitely smoother. in my opinion shell vpower is the fuel that i notice the most difference with!