Can anyone offer me some advice please

I usually use 95ron, but am thinking of treating my Scoob to a full tank of either Optimax or 98ron, what effect will this have on the engine and which one would you use ?? Also is it good practice to do this sort of thing on a regular basis ?? What are the short and long term effects if any ??

My missus thinks I should treat her as often, as she feels I love the car more than I do her any comments on this too would be appreciated is this the norm, I may be single soon.

Newby

 

I wouldn't run it on NUL at all, Always use SUL or Optimax, best to be safe than sorry.

Scoobs usually det on NUL from the factory.....not good.

 

Cheers Dingy, I'll look at putting in Optimax or 98ron in the future... Will using this sort of fuel increase my MPG's ??

Newby

 

Kempo what is Millers ??? Excuse the ignorance pls

 

I put in Optimax when I was running in my new STI 8 and noticed little difference to standard UL.
Now I have done over 2000 miles, and I put some in again.. and the difference was tremendous, much smoother, much happier, both me and the car!
Now I need to see if I get more milage out of the tank (Over 240 would be nice!)

 

Yep, Millers Octane Plus - raises the RON by 2 points to make SUL up to 99 RON and Optimax up to 100.6

One bottle is about £3 and treats a tank.

NF (Nitrous formula) is the other preferred octane boost - never tried it myself though.

Paul

 

I HAVE RUN NUL IN MY UK MY 98 NO PROBS JUST RUNS SMOOTHER ON ESSO SUPER OR OPTIMAX I ASKED THE DEALER ABOUT NUL AND THEY SAID ITS FINE MIGHT JUST BE IMPORTS THAT ARE BEST NOT RUN ON NUL BUT I FIND THE CAR RUNS WELL ON ESSO SUL

 

Newby

What model year is your car?

If it is MY98 or earlier, you will have to reset the ECU to notice any difference. MY99 and MY00 adapt to better fuel more quickly and MY01 onwards adapt more or less instantly.

D.

 

Cheers DJB, she's MY02... I assume I'll have no probs

 

AFAIK, NUL is ok on non modified Turbo 2000 and UK spec WRX's. STi's (Import and UK) should always be run on SUL or Optimax.

In fact, it actually says on the fuel flap and no doubt in the book to always use 98 Ron fuel (MY02 STi Type UK). The only 98 Ron fuel that is available in the UK is to my knowledge Optimax (SUL being 97 Ron). Dealers to state that 97 is just about OK though.

I would not rate warranty chances on an STi Type UK that went bang and was run on 95 Ron NUL...... Dont do it!

James.

 

You will find a difference in the smoothness alone with SUL. I did and I run an MY02. I ran mine on 95 RON for 9 months before making a change. Get PPP fitted and it runs even smoother and faster but then you will be forced to feed her on SUL without a significant drop in BHP and torque.

 

Don't forget points rating on octane booster bottles DO NOT equal RON levels
10 points = 1 RON increase!!!
If Millers are stating a 2 point increase this actually equates to 0.2 RON, so turning SUL from 97 to 97.2 RON.

Rob.

 

I believe Optimax and Millers OP has been tested at 99.3 RON

 

Spend it on the car. Women ain't worth it. At least when you get rid of the car, it won't be asking maintainance money from you. Trust me..

 

On my UK MY03 WRX I'd always had Optimax in the tank for the first 2000 miles. When I had to put NUL in the tank I experienced what felt like a huge dip in performance. Would this be due to the car expecting to get Optimax? (I'm not really sure what the ECU does)

 

In contrast to the above (and its only my experience) I ran my import MY92 WRX on normal 95RON unleaded for 2 1/2 years (and the owner before me for 1 year) with no probs at all. I did try super every now and then but it made no difference (ECU not reset). The new owner is doing the same and has had no problems either. The car is on 80,000 miles and runs sweet. It was Unichipped 8 months ago and the rolling road showed the BHP was 233 before (possibly down to the 95 RON) and then set up to run 263 after, reliably.

The only other mods were total decat and filter.

T.

 

I have heard that running on Normal Unleaded may cause under-fuelling at high revs.. resulting in posible engin damage...
Is this correct??

 

Newby

Shell claim that Optimax can improve the fuel economy mpg figures compared to NUL and there are certainly varying opinions on here as to whether that is true.

In any case, for a full tank of fuel you are looking at 3 - 4p litre more for Optimax or SUL thus £1.50 - 2.00 per tank. This is wholly insignificant compared to the benefits (more power, less det).

I always run my UK turbo on Optimax or SUL and often stick in a bottle of Millers too

Paul

[Edited by Kempo - 4/8/2003 9:44:51 AM]

 

Is it octane boost?

I know Millers make normal oils...but not sure about octance booster

[Edited by Trick - 4/8/2003 12:45:29 PM]

 

Cheers Joop I'll treat her tonight the car that is

[Edited by newby to scooby - 4/8/2003 3:13:23 PM]

 

Ran my MY 2000 UK car on optimax for the first 2 months. But as I'm tight now petrols gone up 5p a litre, I'm running me baby on 95 Ronald normal unleaded. Possibly a teeny bit less smooth but hardly noticeable. Performance seems unchanged and the cars really going well at the moment - Dont you love Summer! As has probly been said above only use Normal unleaded (95 RON) if you have a UK car. Imports, especially the STIs really need Super/Optimax.

Oops forgot to say it seems from previous threads it may take 2 or 3 full tanks of Optimax for your cars ECU to adjust to the luxurious new fuel and give any increased performance!

Ciao,

Cal

[Edited by currymonster - 4/8/2003 10:07:10 PM]