Hi guys, just a quick question....

Has anybody used the high octane unleaded in their Evo?

Mines just a 1.4 8v but wondered if it would be worth a couple more quid and put the shell optimax in, instead of regular unleaded?? :slayer:

It's not worth putting Pottimax in your car really. What gains you would get would be very minor.

Better off putting proper fuel in the car, ie don't use the cheap supermarket fuel. Better to put a quality brand like Shell.

I've seen a few mpg per tank = more miles per tank. Plus I'm sure my car likes it better too!

I only use 95 in my Evo 135. Seems fine to me, not sure it's worth bothering with the 98.

yeh, im just sticking to Shell Unleaded

one thing that is getting on my nreves a little is that when im stationary and the cars ticking over, evry four seconds there seems to be an engine 'rumble'.

its not a crazy shake, just different to the average tick over, it could just be me being picky though?

miura74 said:

I only use 95 in my Evo 135. Seems fine to me, not sure it's worth bothering with the 98.

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It isn't really. The higher octane rating is the fuel's ability to resist pre-detonation and although I've no doubt the ECU has the abilty to tweek the ignition timing it's still primarily set up to run on 95 octane. I had to run higher octane fuel in my previous car, a lightly modified Nissan 200SX with 280bhp. On standard fuel it would 'det' on 95 octane and run the risk of melting pistons.

Higher octaine burns cleaner aswell

Adrian Bravo said:

Higher octaine burns cleaner aswell

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I've put 3 tanks of Shell V Power Unleaded into my Evo Sporting and if anything, the MPG has gone down! I'm not driving it any differently so i think i'll just stick to the normal Shell Unleaded. VAT goes up in January too so Fuel will go up so the V power will get more expensive!!

smokeychops said:

I've put 3 tanks of Shell V Power Unleaded into my Evo Sporting and if anything, the MPG has gone down! I'm not driving it any differently so i think i'll just stick to the normal Shell Unleaded. VAT goes up in January too so Fuel will go up so the V power will get more expensive!!

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Fuel prices here go up and down several times a day. Which is annoying as you see a cheap (ish) price, driving one direction. Drive back later to fill up and the price has gone up.

Bumping an old post!

Has anyone actually figured for a fact if the Evo can take advantage of RON 98 fuel or not yet? (even the Sporting, or Abarth?)


Just something i've been wondering, I've seen no mention of ron98 in the manuals etc so i'm guessing not, but would be interesting to know for sure & as we have people making chips etc now im sure they must have played with such things...

If people start running a lot more boost it would make sense as charge temps and cylinder pressures go up but I wouldn't bother otherwise. I used to have to run my 200sx on it before the sporting and that stuff isn't cheap, the price of it seems to climb a lot more than regular fuel.

Marcos999 said:

If people start running a lot more boost it would make sense as charge temps and cylinder pressures go up but I wouldn't bother otherwise. I used to have to run my 200sx on it before the sporting and that stuff isn't cheap, the price of it seems to climb a lot more than regular fuel.

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aye tis pricey stuff, i use it on occasion just to keep things clean.. usually run normal unleaded though... just curious as to weather anyone knows if the ECU scales to different octanes etc.

'Normal' unleaded is 97RON, and from what I've noticed, only Tesco's seem to sell 95RON as their 'normal' unleaded. Vpower is 99RON AFAIK. Ironically, my local Shell is cheaper selling 97 RON than my local Tesco's and their pikey 95!

Granted the ECU can cope with 95 and adapt, but it'll be far happier and consistant on proper 'Premium' 97.

We had an Astra VXR with power readings 20-30 bhp down and really inconsistant throughout the dyno runs. Turned out it was on 95RON. Drained the tank and refilled with normal 97 and the power returned and was smoother as it wasn't constantly going into knock retard.

As for Vpower in a normal non-turbo engine? The differences are going to be negliable as the intake temps and engine load isn't as extreme, although personally I could definately tell the difference between Tesco's 95 (was desperate) and Super (98) in my 1.2 daily hack.

D4nny8oy said:

I could definately tell the difference between Tesco's 95 (was desperate) and Super (98) in my 1.2 daily hack.

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:yeahthat: car has more poke (if the 1.2 8v can have such a thing) and returns a slightly better MPG IME (and i have played about with it more than once)

Tesco is 95Ron & everywhere else is 97+ ?

Is that all supermarket petrol or just tesco? (i know tesco are considered the worst, just never knew why exactly)

Just look at the label next to the pump, every fuel station I have used says the rating. I can't say for all supermarkets, but my local Tesco is 95 whereas Morrisons is 97.

How fresh a fuel is also makes quite a difference, it's worth going to a busy station.

I'm not sure if it is a requirement but 99% of standard unleaded is 95RON. Super can be anything over 95RON, typically over 97RON with Vpower being 99 here and 100 on the continent.

If your engine is modern enough to incorporate a knock sensor and be able to adjust fuel timing then the engine can take advantage, however without increasing the boost on a turbo, you won't really see the power advantage. A N/A car will see almost zero power increase. The major benefit for N/A and low boost turbos is the fuel does burn cleaner and will reduce soot buildup. Many garages comment that they can tell, providing the engine is running correctly, the difference between a car ran on standard unleaded and a car which has ran on super.

andrelowe said:

yeh, im just sticking to Shell Unleaded

one thing that is getting on my nreves a little is that when im stationary and the cars ticking over, evry four seconds there seems to be an engine 'rumble'.

its not a crazy shake, just different to the average tick over, it could just be me being picky though?

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I feel it too on my 1.4 8v evo, Ive only had it 4 months so I thought it couldnt be anything major. I was thinking maybe it was just the engine fan, or i could be totally wrong

I've alway run my lexus on sainsburys super which is 98 Ron and it ran ok but on 95 it run crap.

Don't know what the difference would be on sporting or abarth need to ask to may dealer when I pick my new abarth up