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!!! :)

To be honest since i bought mine a few weeks ago i've been running it on both and i can't tell the difference.

 

I need to try 99 ron but nobody sells it round here

My car is std except for the rust and broken bumper :wack: and I cant tell the difference between Optimax and normal 95 Ron.

yeah i put super (all make's) in my lotus then put tesco 95ron and boost went from 0.9bar to 1.1-1.2bar and it was fast'er and NEVER went to "limp home mode" 4000rpm max

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!!! :)

Check your mpg - I guarantee it'll drop ;)

ive ran mine on normal unleaded since ive got it and ive never had ANY det.

oooo, I don't think I'd dare run mine on normal unleaded for long, perhappes the odd few gallons if I couldn't get anything else. Optimax and Tesco's 99ron for my baby. Japonica gets only the best. :dance:

RON is a measure of the fuel's resistance to detonation - deciding to switch to lower octane fuel with the recent weather (i.e. hot) is just asking for trouble!!

I completely agree with Rich66! Absolute madness to swap to a lower octane in this weather. You don't always know if you are killing your engine until its too late. I wouldn't risk it unless you've got a very clear reading of the temps etc eg EGT gauge, coolant/oil temp etc. You wont have issues running day to day, you'll get issues either when you give it welly or when you are stuck in traffic. The engine will get hot and then the combistion will get out of control at a lower temp than it would with a higher octane petrol.

I completely agree with Rich66! Absolute madness to swap to a lower octane in this weather. You don't always know if you are killing your engine until its too late. I wouldn't risk it unless you've got a very clear reading of the temps etc eg EGT gauge, coolant/oil temp etc. You wont have issues running day to day, you'll get issues either when you give it welly or when you are stuck in traffic. The engine will get hot and then the combistion will get out of control at a lower temp than it would with a higher octane petrol.

Totally agree with you no point taking the chance with a lower octane fuel. Look after your engines guys and they'll look after you.

Check your mpg - I guarantee it'll drop ;)

 

I get about 10% more MPG on my NA with super / Optimax.

 

It works out cheaper than regular unleaded so I always use it if I can.

agree with rich666, my question to all those who say "i dont get det" is this...... EXACTLY how do you know this please, i'm assuming you have a guage to tell you the det levels??

 

also, if your car has been mapped or set up for 98 ron then its not advisable to use 95 ron i wouldnt have thought..

 

T

you can get aftermarket knock sensors, these work through the rev range, unlike Nissans own det sensor that I think only works below 3K rpm.

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

To fill up from empty with Optimax or BP Ultimate it costs about an extra £3-4. Surely your car has derserved some of the good stuff!

 

BP Ultimate claim that you will have a cleaner, more effecient engine, gain more power and have a better mpg.

 

http://www.bp.com/modularhome.do?categoryId=6620&contentId=7009602

 

I recommend filling up with the good stuff!

ok ok ok ok ok Im convinced to switch back :)

Always have put it in and for the extrta few quid its worth it for piece of mind for the engine.

Not sure about the mpg though - havent really noticed its any worse on unleaded.

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.

one more thing though - without doing the whole optimax thing to death - doesnt it lose octane quicker - i.e. tanker delivery delivers on saturday and by the following friday the octane is not guaranteed at 98?

The other week I went to my nearest shell garage and they didn't have any Optimax :( so I turned around and went to the next nearest Shell and they didn't have any either :( :( By this point the petrol warning light was on so I put £5 of normal stuff in so I could get to tesco and put 99RON in. Anyway, when I was paying for my whole £5 of fuel I asked the guy why there was no Optimax and he said they had stopped selling it for a few days while they changed it to 100RON :) Don't know if this is true or not but it came from an employee of Shell so it could be, although I've not seen it advertised anywhere so prob not.

 

Rob.

he said they had stopped selling it for a few days while they changed it to 100RON :)

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..

Wow, that would be nice, you could up the boost a bit and stay safe.

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.

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.

only ever use super , esso supreme or optimax , your car may run ok on unleaded but you never know what your timing is doing whilst you are driving it, you may lose a degree or so of advance without any noticible difference on normal unleaded but i prefer to run on the safe side which is what high octane fuel is about

yeah i put super (all make's) in my lotus then put tesco 95ron and boost went from 0.9bar to 1.1-1.2bar and it was fast'er and NEVER went to "limp home mode" 4000rpm max

 

 

tesco's petrol has cleaningfluid in it. that is probably why your boost went up as the petrol has cleaned your engine a little bit... best not to use all the time. one in every 5 tanks is good enough...

stick to the cheapest myself ( being a yorkshire lass, eh jay??!!)never had any issues at all, considered higher octane but can not see it makes all that much differance myself

Only run mine on Super and it goes great, wouldn't risk putting lower in, unless it was an emergency