Ok. Heres one that has had me going for a bit. In the States i believe premium gas is 93 octane right? Here in Europe it's 98 octane. Now my question is, If i get an FI kit from the states tuned to local gas octane, and i stick it in a Z running 98 octane would there be any issues. I am refering to a stock out of the box kit. My theory is that there would be no problems, only the car would be running SUPER safe at a very low risk of detonation, right? What do you guys recon?

 

Thats correct. But is your fuel 98 MON or RON or R+M/2
USA fuel is either 91 or 94 octane r+m/2

 

Sharif, what if you are tuned for 92 octane but switch back and forth between 92 and 100 octane? Any problems doing that? Would the ecu advance/retard timing? I'll be tuned using the unichip.

 

better than being tuned for 100 octane and switching back to 92

 

98 octane just means u can up the boost.

btw...in my sig, the numbers were tuned to 96 octane only.

 

Your timing wont change, unless your stock ECU was detective knock on 92 octane, and retarding timing. In that case, you will make more power with 100 octane, as your stock ECU starts to advance the timing...due to the lack of knock.

 

Thanks Sharif.

 

This supposably happened to me causing me detonation. My APS TT car was tuned at 9 psi on 91 octane cali crap gas. Thinking I would just be extra safe ( enjoy fast spool up from the added octane ) I ran VP 109 Octane fuel every so often. When I returned to the straight 91 octane I was told that the Nissan ecu added timing ( while running 109 ) and neglected to pull it when I returned to the 91.
I have since had my car tuned for 100 octane at 13 psi. I hate the fact that I was not able to hear my car detonating. I took the car in because of a loss of performance and found this out

 

What happened to you is exactly what I was worried about. It would seem that tuning is the key to preventing this scenario. As Sharif said, if the tune was proper and not knocking, then timing would be unaffected.

 

So you believe that as long as your tune is solid from the start- then your stock Nissan ECU should not cause a problem as it varies timing with changing octane???

 

Correct. If the tune is solid (no knock) then the ecu should already be utilizing the advanced timing map. Therefore, if you increase the octane, the ecu will continue to use the same timing map. Mind you, I'm basing this entirely on what Sharif stated above.

 

I thought that the Octane rating (how they give the rating - 98 Europe doesn't = 98 US) in the States and Europe where different? I think I remember that when I looked at sending my car over there for a driving vacation that never worked out.

 

I´m not really sure to be honest, all i know is that we pay $1.50 per litre (not gallon) so it better be the good stuff. I´ll try and find out for you.

 

Man that sucks. I´ve just been reading about fuel octane ratings, and hear in Europe they use RON. So basically even though our octane rating is 98 RON, if that were to be converted to US spec R+M/2 that equates to about 94 octane. Now i realise that weve been conned all our life!!!

 

If running a Utec, will the stock ecu still make adjustments while in boost, or does the utec fully take over after idle ?

 

Fully takes over in the boost....stock ECU wont do anything with timing. The UTEC will still retard timing if knock is present. All of this is user/tuner adjustable, which makes the UTEC very versatile for tuning.

 

I have 93 Octane available in my area. But if I drive out of my area, I'll only be seeing 91 Octane. I'm getting my car re-tuned in a few weeks. Should I get it tuned for 93 Octane or 91 Octane to be safe (just in case I take the car out of town and 93 isn't available)?

 

I think its always best to get it tuned for the lower octane just to be extra safe