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Discussion Starter · #1 ·
I've been using Tesco 99 Octane for months, but yesterday filled up with Esso 97 Octane 'Supreme' fuel, and the GTi actually runs far better on the Esso fuel. Definately pulls harder, and seems to run more smoothly than before.

I'm so shocked by the difference, that I'll try to avoid Tesco-Value petrol in the future.

Anyone else had this experience?
 

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When I had my 172 ages back I noticed that on Sainsbury's "super unleaded" it wasn't nearly as good as Shell's, though, in that the difference wasn't really noticable.

Can't comment on my GTI cause it's not built yet :( , but will be soon :)
 

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To be honest, I can't see how anyone can notice such a difference between different fuels.

I have had several quick cars and motorbikes, and have never been able to tell on any of them that one fuel is notably different from another, especially those with the same RON level. The only difference I can see with Optimax is that it smells different from the exhaust.
 

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Never tried Esso 97 Octane ' Supreme ' fuel as VW recommend 98 Octane for the GTI

Have always used Optimax but I remember reading somewhere that in a one off test BP Ultimate 97 produced a slightly better BHP than the Optimax ?

I'm sticking with the Optimax though.
 

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Discussion Starter · #6 ·
> To be honest, I can't see how anyone can notice such a difference between different fuels.

I used to be of the exact same view; "it's Petrol, it burns". BUT, after using Esso Supreme, I'm quite certain that the difference is plain and easily detectable.
 

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Could it to be Sulphur content?

FSI engines require ultra-low Sulphur fuels. Perhaps the cheap Tesco stuff is not as good in this department.
 

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The tesco's 99 ron fuel is very low in sulphur it is one of its selling points.

I found ultimate is the best stuff in mine especially for low down torque response, on optimax and tesco 99 I have found it to perform better up the rev range without such a strong low down torque response.

Esso 97 I found to be flat with my car and the station I use so dont normally bother with it, you could also construe that as smooth but it feels as if the car is pulling timing, so I stear clear of it.
 

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Evo magazine tested different fuels in a GTI a few months back, and I've listed their results below (brand, max power, max torque):

Shell 95
205bhp
234lb ft

BP 95
204bhp
242lb ft

Shell Optimax
209bhp
242lb ft

Tesco 99
212bhp
242lb ft

BP Ultimate
212bhp
252lb ft

Sunoco Race Fuel (352.5p/litre!)
218bhp
248lb ft

Make of that what you will.
 

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Hmmm that's interesting. I run mine on Optimax or Tesco 99, and both are obviously a hell of a better drive compared to 99. I ran through a full tank of Ultimate from BP at one point, and talk about absolutely crap ride. So now that Esso's been mentioned, I wonder if it is any different [y]

C
 

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had two tank full of the tesco stuff, and got extra mileage which was reminiscent of 95 octane from jet or total

optimax is much better in my car, dont get the high miles but the performance is excellent, can immediately tell the difference after putting optimax in

just my 2p worth
 

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..I think that in some cases, especially with Supermarket fuel, you can never be 100% sure about what exactly you are getting, they tend to buy in the cheapest fuel of the same RON and just use that. I'll be using Optimax when mine turns up, but you always wonder if someone at Shell is just rubbing their hands together, looking at the the car enthusiasts and thinking.... "hahaha suckers!". I too had a 172 and hardly noticed the difference between Shell 95 and Optimax. I've also heard that your car takes time to adapt to a new fuel, how long this takes (and if it's true) I don't know, but you do end up wondering if there REALLY is much difference, or if it's just psychological.
 

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from what i have heard, it takes two tank full for the car to adjust to the new fuel, but i do notice the difference quite quick
 

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Filled up with fresh tank of Optimax the other day.

Gave it some welly out of the garage and boy did it pull!

So much so....I want more boost and bigger kick! [:D]
 
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