last week - Religously been using it since I had the car.

 

Its mildly tuned (Exhaust, filter boost upgrade and aggressive JD Chip).

 

Decided to try normal unleaded in it and it runs sweet as (just cheaper)

 

Cant tell any performance difference and Im not getting Det!!! :)

Thats probably the car going into safety boost due to det? Its a fair point though, if its a UK zed then it should work ok on normal unleaded. With the heat under the bonnet though I'd never consider using it.

 

Having a Uk car that is stock, save for filter and exhaust I normally use regular 95ron unleaded. Afterall the car was originally set up to run on the stuff.

 

I occasionally use Optimax or BP Ultimate but TBH I don't really notice any difference either, save for slightly better economy on a long run. But then I find Shell in general gives better MPG than other brands, both in my ZX and Merc SLK.

 

However during very hot weather (say 28 degrees plus) I have very occasionally experienced safety boost - probably down to detting. Optimax did cure the problem there, but under most circumstances there is no safety boost probem so regular u/l works fine for me.

Richard :cool:

When I bought my Zed the guy I got it from said that he used regular unleaded and that's what the car was set up for. So I did.

 

But...

 

When I gave the car 'full welly' the engine would sometimes back off half way through boost in a big way, which made me think that something was wrong. I decided to use Optimax for a few tanks just in case and 'hey presto!', the boost problem has gone and never come back.

 

I heard that all Jap cars would be set up to run high octane fuel as that's just what they sell over there? And hideous low octane in the US, but that's not really relevant.

 

There was a thread about the US stuff a few weeks back. Don't be fooled by the low octane number. Their octane number is not the same as RON, so their 93 octane fuel really is super.

There was a thread about the US stuff a few weeks back. Don't be fooled by the low octane number. Their octane number is not the same as RON, so their 93 octane fuel really is super.

 

Really? I'd heard from a few sources (including my mate who has an import Mustang with what the Yanks would probably call a 'weedy' 3.6) that their petrol was cack. Is their regular petrol similar to ours then? I was surprised to hear that their petrol was lower octane than ours, as the Americans don't really do half measures on anything usually...

dangerous knock occurs under load in the high rev range when the turbos are screaming out usually, Nissans knock sensor works well at all revs (on the skyline anyway) and is usually a decent indicator as to what is going on, although not infallable...

 

cars that are mapped by a professional usually have a safety margin factored in to try and minimise damage due to detonation, this is usually done by richening the mixture at the higher revs and or not being as agressive on the timing...

 

if a car has been mapped using optimax and you change the ron then as far as i am concerned you're asking for problems..

 

all the best..

 

Tony

ime sure on the 300 tony the knock sensor only works upto 3000rpm and its by then iff it picks up knock it starts the decline in smile factor :( . on the octane subject after detting on a regular basis i started asking a few mates in the forcourt trade and i dont want to piss you off guys but iff the shell franchise places cant get optimax fast enough they "outbuy" and in goes normal unleaded :mad: i shiit you not!!!!!!!!

Shell sell 100ron V-Power on the continent but there's nothing on their web site about it being introduced over here :( It's been rumoured for a while now so who knows..

 

Hope its cheaper than the £2.50ish BP102!

My nearest Shell Optimax is about 8 miles away, and my zed is my daily drive, but its 8 miles in the wrong direction from where I go :(

Cheers people.

 

My nearest shell is 8miles away too dude, but I just fill the Z up with £25-£30 once a week then it lasts me... It's what me and my house mate with his Civic Type R now call "The Optimax run" which we tend to do every Sunday night!! Look forward to doing that run once a week!!! The girl that work behind the Kiosk is well fit too so worth the drive!! :D

 

Although a few pence more than normal unleaded you def get better MPG with Optimax and also all the performance benifits... :bow:

I started using 'Esso Supreme' a while back, as I noticed I didn't get as such a strong unburnt fuel smell when I boot it a bit as I do with Optimax/Tesco 99, but only noticed the other day that Esso Supreme is only 97 ron ??

 

Back to Optimax I suppose :confused:

well i have a UK spec so i can use the normal unleaded if i want :dance:

 

However i never do, only ever put optimax in mine since ive had it :smash:

dangerous knock occurs under load in the high rev range when the turbos are screaming out usually, Nissans knock sensor works well at all revs (on the skyline anyway) and is usually a decent indicator as to what is going on, although not infallable...

 

cars that are mapped by a professional usually have a safety margin factored in to try and minimise damage due to detonation, this is usually done by richening the mixture at the higher revs and or not being as agressive on the timing...

 

if a car has been mapped using optimax and you change the ron then as far as i am concerned you're asking for problems..

 

all the best..

 

Tony

i agree, the suggestion of knocking occuring sitting in traffic is rediculous. if your having problems at idle then you have WAY larger problems than the fuel in the tank. in fact, if the timing was such that it would knock at idle, the engine wouldnt even tick over.

if the timings ok, the engine is std and running properly then i doubt ud get any probs by running unleaded.

I started using 'Esso Supreme' a while back, as I noticed I didn't get as such a strong unburnt fuel smell when I boot it a bit as I do with Optimax/Tesco 99, but only noticed the other day that Esso Supreme is only 97 ron ??

 

Back to Optimax I suppose :confused:

 

an engine thats healthy and has no problems shouldnt smell of unburnt fuel, again, i think fuel is being used to cure another 'sick' car