Thread: A P38s' preferable octane

There is no way known that a higher quality fuel ie 98 octane can do an engine harm.
It does take your engine management system a little time to get the most out of it as it adjusts to the better fuel.
As for using ethanol fuel i can categorically state that in 12 years of using PLUS ULP i have not had a single issue with ethanol based fuel.

I'd stay with 95 octane. Didn't use 91 if there was another choice

Gary

Originally Posted by RR P38

There is no way known that a higher quality fuel ie 98 octane can do an engine harm.
It does take your engine management system a little time to get the most out of it as it adjusts to the better fuel.
As for using ethanol fuel i can categorically state that in 12 years of using PLUS ULP i have not had a single issue with ethanol based fuel.

I run e10 when i first got the P38 and after around 12 months killed the fuel pump as a result. According to the VACC website, it states that all petrol Land Rover vehicles post 1986 are suitable to run on both e5 & e10, but as a rule of thumb, any vehicle built before the year 2000 i personally would not recommend using the e10. Vehicles before 2000 were not manufactured with e10 in mind, and even though it may be ok from a VACC's point of view, the long term effects have still not been tested, and will most likely raise it's ugly head when you least expect. Even vehicles built between 2000 - 2005 you'd want to double check just to be sure as when i last looked on VACC, i noticed some Hyundai models to be unsuitable right up until 2007, so it pays to check. As far as octane, 91 seems to be the flavour for the my 96 4.6. I did notice a slight decrease in economy (would you believe it!!) when running on 95, but noticed the cleaner, less smellier running, not to mention a smoother acceleration. 98 octane is merely a waste of money as that fuel is really made for high performance engines think Ferrari, HSV,FPV, Porsche type cars. Would probably make the P38 run worse with such a strong fuel.

Just buying a 97 4.6 and on picking up need to full it up. Not sure what compression she is...choices are 91 or 95 Octane. Sounds 'safer' to just got with 95? Can get 98 but only at BP.

I have had both low and High comp engined cars, always run std ulp 91 with no issues. The high comp car is LPG so dont use much petrol but when I do it runs sweet. Your car will most likely be low comp

Ah righto...don't mind paying for premium but if it doesn't make ANY difference...

I agree with Wayne, 91 octane on a GEMS motor. It's most likely a low comp motor. I only ever use 91 in mine.

Gary

My MY99 bosch owners manual specifies 95 RON so I use that.

There are quite a few sad stories about E10 and P38 fuel pumps sadly

Steve