has anyone noticed any real difference?

shell garages are not very common around here, (unless someone knows otherwise?) so so its tesco all the way.

discuss!! <img src="/forum/images/graemlins/laugh.gif" alt="" />

I always run mine on Optimax and now the V-power stuff from Shell, IIRC it wasnt just the improved octane on the shell stuff but they somehow made the fuel lighter ?
I cant remember the full story but it was something to do with F1 and reducing the weight of the fuel. It enables you to carry that extra packet of chocolate hob-nobs around with you without losing performance <img src="/forum/images/graemlins/wink.gif" alt="" />

hmm....the problem is ive never really been a fan of the chocoloate hobnobs, ill try the oaty ones and see how it performs, they are lighter too so surely even better economy/performance?

<img src="/forum/images/graemlins/laugh.gif" alt="" />

ooh it was developed by ferrari, it must be good!!


on a serious note, has the tesco fuel ever been tested or commented on anywhere? my nearest shell is miles away, all i have is BP ultimate locally.

<img src="/forum/images/graemlins/smile.gif" alt="" />

Tesco 99 RON is made by greenenergy, and is meant to be pretty highly respected.

Some results here sugest it is better than Optimax:
http://www.thorneymotorsport.co.uk/gcs_a...t%3D0%26toc%3D1

Having said that shell have just switched to v-power, which is advertised as 99RON, so it may be that they are more closely matched now?

I always use shell, as I don't have a Tesco near me <img src="/forum/images/graemlins/crazy.gif" alt="" />

For making most power on a mapped car V-Power is much better than Tesco 99.
The Tesco stuff is partly bio-ethanol based wheras V-Power is not, so there is an argument that the Tesco fuel is 'greener'.

The det properties of V-Power are better so you can run more ignition advance on it.

BP Ultimate apparently could make more power on like-for-like ignition advance, but because you could run a lot more ignition advance on Optimax that meant the best absolute power you could get partly depends on the static compression ratio of the car and the benefit of running more ignition advance. The higher the comp. ratio the more beneficial ignition advance is in terms of power.

V-Power is some way better than Optimax BTW

If you have a Unichip you should try to always run on the type of fuel you got it mapped on, or better - so if you got it mapped on Optimax or V-Power you should not try to run BP Ultimate.

Rog, I find Tescos 99 fuel to give me the strongest midrange, Optimax is similar to Tescos at the top end.

Joe

Joe - which was your car mapped on? I think you mean V-Power

yes guys, i used the word optimaz forgetting that its now V-power.

i did suspect that V-power would be the better choice.

im not running any ignition advance off of the unichip at all, but im hearing some pinking at higher boost (1.3 bar) on 95 ron fuel so will run some 99 to see if it stops.

cheers guys.

<img src="/forum/images/graemlins/cool.gif" alt="" />

paddy's link is interesting.

the tesco fuel gave the best increase, although it was in the days of optimax and not the new v-power.

bp ultimate also made a strong show on their tests.

ofcourse, they are different cars with more modern management, but interesting to read.

Yeah, some of the newer cars can adapt much better to diffrent fuel qualities.

I think on some of the newer cars, the ECU can get a reading from the spark plugs, as to the amount of electrical resistance whilst the plug sparks. This can give the ECU a clearer picture about what is going on in each cylinder <img src="/forum/images/graemlins/cool.gif" alt="" />

Is the 20VT ECU adaptive? will a standard chip make changes when given a good quality high octane fuel, or is it just much less likely to retard the ignition due to it being less likely to sense detonation occuring? Is the only way GTEC 2 / unichip / re-map?

A stock chip cannot make the most of the advance, the only benefit is if the fuel generates more energy at the same max advance level. On GTec2 I think Graham has dialled in some more ignition advance so it may be able to make some use of it. But I'm sure it isn't making full use of it

Rog - if your car is pinking then it would always be a good idea to run a better fuel

It is fair enough to test standard cars (as in that article), but if you are getting your car mapped then it is a whole different ball game. Also turbocharged cars are also a little bit different in that we have a much lower static compression ratio to start with but higher 'dynamic' compression (for obvious reasons!)

But - in reality - we will notice a big difference on a Novitec/Gtec-chipped 20VT, as long as it still has it's std. boost management (EBV).

With a reset ECU I get around:
99octane V-Power: 1.4bar
98octane Jet: 1.3bar
95octane Jet: 1.1bar (on hotter days even less)

I run the Novitec chip + clean EBV.. <img src="/forum/images/graemlins/cool.gif" alt="" />

John, it has almost always been mapped on Optimax 98ron, although I think it had a combination of the two last time.

joe

If you want compatibility with all three (BP Ultimate, Tesco 99 and Shell V-Power) you should get it mapped on BP Ultimate as that has the poorest det properties of the three, so will take the least ignition advance.

I'm due a remap soon (GTEC2/Unichip/V-Power), what will be the consequences of using BP Ultimate or Tesco99 if the ignition advance is at the max? Ok short term but could cause problems long term?

If you use a poorer quality fuel you'll probably get det.. which is bad. However it is really down to the mapper to set the car up to be 'safe'.

I was reading a cached version of DocFrag's aquamist post yesterday and Paul at PTS would wind his ignition back to stay safe if he ever got a bad batch of fuel etc.

For the record, i've run both these fuels for at least 5 tanks before switching to the other fuel. My drive is mainly stop start through London and i noticed my average run on a tank was 280 using Tesco99 and it was 320 using optimax (as it was back then). This was running on a Gtec1 and SMIC.

Totally agree with Ken's findings on MPG. Get much better mileage out of the V-power. On both cars. Like Rog though, sadly the nearest Shell garage is miles away.

Im going to have heart failure the first time i fill up on this stuff <img src="/forum/images/graemlins/cry.gif" alt="" />

Think V-Power's bad? Go fill up a handful of times on BP102. £121 per tank! <img src="/forum/images/graemlins/shocked.gif" alt="" />

Yeah but thats just silly unless your going to get mapped on it and use it on the track....

tesco 99 works for me!!

I have used nothing but v-power in my new engine and personally its very responsive!!!

Ross

You guys might find this intresting.

http://www.peterbetts.co.uk/Fifth_Gear-Thor_Racing.avi

But the cars being tested can detect the different RON rating. The GTI is meant to be run on 98 all the time, so running it on anything else is going to lose power, so not really a conclusive test

So is teh scooby iirc coming from the east its meant to have higher stuff anyhoo.

They could have done with showing the cleaning properties and a car after say 30k miles on the power runs as well...