The first time I filled-up with Tesco Momentum 99 RON, the car felt more lively and powerfull even yards from the forecourt....but I know that's technically very unlikely if not impossible, since the ECU wouldn't have adjusted itself that quickly.

Like Rob's lawnmower, I think there is a certain perceived placebo effect. I certainly think I can feel a difference, but have never measured it or even noted the MPG difference.

More scientifically, one of the car shows (Fifth Gear I think), done a comparison a few years back. It turned out the Tesco 99 RON stuff rated best on performance Vs. Price, but they stressed you'd only find a difference (and only slight) in a performance car.

Interesting

http://www.thorneymotorsport.co.uk/media/press/Thorney_Motorsport_Withdraws_Recommendation_for_Tesco_Momentum_Fuel.shtml

Probably a sponsorship disagreement John's turning hell of a greedy of late, plus he's rubbish at the BTCC

More scientifically, one of the car shows (Fifth Gear I think), done a comparison a few years back. It turned out the Tesco 99 RON stuff rated best on performance Vs. Price, but they stressed you'd only find a difference (and only slight) in a performance car.

Was it scientific enough though that they used the same car, in the same weather conditions, and they flushed out all the previous fuel?

"Performance vs price" is also important - it presumably relies to an extent on the Tesco fuel being cheap!

Evo magazine did a test, pretty much as scientific as possible, same car, same day, flushing the fuel etc. IIRC they tested both a Golf GTI mk5 and a BMW (m5?). No difference on the bmw but the GTi I think gave increased bhp on v-power.

http://www.google.co.uk/url?sa=t&source=web&cd=1&ved=0CFMQtwIwAA&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DgQghB4asSnI&ei=Ta4NUPrJBamN0AWIoYGtCg&usg=AFQjCNFKXzFDuJeEXDQyfW0EbppGLPGLog&sig2=CudWtt62-JFA7giEvpIVXg

Been various tests over the years, all different, none exactly conclusive.

Was it scientific enough though that they used the same car, in the same weather conditions, and they flushed out all the previous fuel?

Didn't see the petrol one, but they did a diesel one awhile back testing supermarket, BP and Shell premium with a C3 by measuring the turning power on the drive wheels (essentially rolling road), and having flushed out the previous fuel. The Shell/BP premium fuel developed about 3% more BHP (realms of reading error?). Not that I actually care - I use Shell cos it's right next to the office, and the same price as the local Esso/Tesco station (but more convenient!).

Probably a sponsorship disagreement John's turning hell of a greedy of late, plus he's rubbish at the BTCC

Re Tescos I know there is more to it, from what I know I would take the latest advice from John.

Like most things in life you get what you pay for, if its cheap question why. For Shell, BP etc their major business (excluding exploration, drilling & refining) is fuel so they will try & offer the best at the best price, Tesco just pile it high & sell it cheap & screw all suppliers for the min quality they can get way with selling for max profit. Few people could proove in court they solely used the tesco brew in their cars so any long term effects unless catastrophic will never be prooved, secondly people look at the price per litre & never think to look at differing mpg for different suppliers, that calculation is beyond the majority of motorists. thus the forecourt price is all mr average worries about but its all personal choice, thats the beauty of it

Re the BTCC agreed, that leaves "significant room for improvement" as I think John is the first to admit

Edited 24 July, 201213 yr by Stuart_J

Most fuel is made in the same refineries. Its not like Shell have some super high tech facility just making V-Power, its the same stuff with marginally different additives.

I was getting my new car remapped from stock to K04 a few weeks ago and we ran in to some problems on the diagnostics where the car was pulling too much timing and a bad batch of fuel was suspected. I used Momentum 99 and VPower so had to go back to my bank statement to confirm that I had filled up with VPower on that occasion. The tank was run down and then filled up with more VPower and all was well.

In short, remapped cars most definitely need higher octane fuel but this looked like quite strong evidence of a bad batch of VPower. I have also felt my older TFSI K04 car struggle on more than one occasion with what I can only believe was a bad batch of Momentum as the next tank load put things back to normal.

I was getting my new car remapped from stock to K04 a few weeks ago and we ran in to some problems on the diagnostics where the car was pulling too much timing and a bad batch of fuel was suspected. I used Momentum 99 and VPower so had to go back to my bank statement to confirm that I had filled up with VPower on that occasion. The tank was run down and then filled up with more VPower and all was well.

In short, remapped cars most definitely need higher octane fuel but this looked like quite strong evidence of a bad batch of VPower. I have also felt my older TFSI K04 car struggle on more than one occasion with what I can only believe was a bad batch of Momentum as the next tank load put things back to normal.

Interesting ! I had issues with V power a few weeks ago, the zed kept dropping into limp mode, bought from the Amesbury shell near stonehenge. Next tank from another garage was fine

Momentum consistently gave issues in the past so wont touch it

I'm running my TFSI VRS on Tesco Unleaded for the first time this week as I was running a bit short on cash this month so the car had to make do without the good stuff...

It seems to be running perfectly normal to be honest, but will be going back to 98+ when I fill up in the next few days! Ultimately the car has a knock sensor or two and will adjust timing accordingly.. the car may not produce quite as much power, but should run just fine.

This thread on Pistonplebs may enlighten a few, I have copied it below & hi-lited the interesting bits

http://www.pistonhea.../t...3F??&mid=0

"If you use Tesco Momentum vs. Shell VPower, you should find slightly poorer MPG with the tesco fuel.

It's possible you may also find mild running problems with carb engines, however with fuel injected engines there is no reason as such that you should find problems - however it does depend on the way injection is calibrated and to some extent the way it is implemented for each particular engine. So it's entirely possible that some models of FI engine just don't like the tesco momentum product.

There's a couple of reasons for this but it boils down to a litre of tesco momentum has a lower calorific content than a litre of vpower.

The base petrol for VPower (and BP ultimate) product is made in an expensive refining process, it's relatively expensive petrol because for a litre of crude very little of the fractions distilled is usable petrol. Everyone seems to know about the additives packages, but in reality these account for only a very small portion of the fuel, and by volume these additives are mostly detergents.

The base petrol for Tesco Momentum, as produced by the Greenergy company in the UK, is made from a cheaper fraction of distilled crude. In fact it's not really petrol to begin with, at the distillation phase it's a fraction known as naphtha. This isn't worth as much as refined petrol, however via reforming (specifically cracking), naphtha can be upgraded to high octane petrol. When married to a larger additives package by volume, you can iron out most of the problems with this approach.

The net result is a mostly comparable product, which is much much cheaper to produce.

Just don't pay vpower prices for momentum and you are probably getting a fair enough deal."

Edited 25 July, 201213 yr by Stuart_J

Sorry as I'm sure everyone know this.

I don't know if it's still the case (as I'm now running Diseasal Scout), but in the past with VAG cars you could easily find out what worked best in your vehicle. On the inside of the petrol flap is the notification of what fuel the car can use.

if it says 95ron, then thats all you need and you are not likely to see much change for running super unleaded.

If however it says something like 95ron/98ron (note the one that is in bold!), then not only can it use 98ron, but by being indicated in bold it is the preferred standard. The indication shows the vehicle can run on 95, but you may notice performance differences. SWMBO had a 1.4 16v Fabia like this, and it would pink under load and feel sluggish if used on 95. No such issues using 98+.

If the filler flap just says 98ron, then that is what must be used, although most handbooks say you can use 95 ron in emergencies for very short periods.

In summary, if your car has knock sensors & can adjust its settings, then they can "exploit" the benefits of higher octane, wether you notice it or not may be the issue!

Simply going from 95 to 98 you may not notice the difference until the tank is flushed through and the detergents have done their thing. If you want to try 98 after 95, go for 2 or 3 full fill ups of 98, see what you get and then drop back to 95, you may well notice more of a difference that way.

Tuners I have spoke to always say put v power in. We map it to that.One guy had Bps ultimate in his TT and he said you should have spoke put v power in

I'm at stage 2 on performance mode 3 and on a few occasions suffered from multiple cylinder misfire. I was running Tesco 99 at the time so switched to V-Power and haven't had the same issue since. Luckily they're close to each other so prices are the same.