28 replies to this topic

[argi]

i use on my n/a 98 or 95  BP or SHELL never had any issues, freeway 510klm and city 415klm (50L tank)!my subaru manual book says to use only 95 or 98!

cheers!

ARGI!

[U-Shell]

Seen too many people need to replace too many things because of ethanol. I'll never use the stuff!

I didn't think it was the fuel itself? Doesn't the ethanol lift gunk up from the bottom of the tank and as a result the gunk is what blocks and breaks filter and pumps etc?

[Dimeb4g]

I have run 98 in nearly every car I have ever owned... And 98 only in my b4 for many obvious reasons!!!
I
My mrs runs 98 in here mazda 3 and consistently gets over 700km from a tank which is combo city and some highway 100km driving (maybe 10km highway driving each way) she only gets about 670ish out of a tank on 91...

My understanding is that because it is a denser fuel, and has more octane molecules it would make more bang from less fuel... Therefore not requiring as much volume to produce the same bang... Hence saving fuel...

[Cam.]

Lol...

[tmh983]

My understanding is that because it is a denser fuel, and has more octane molecules it would make more bang from less fuel... Therefore not requiring as much volume to produce the same bang... Hence saving fuel...

lol, u are so far off the mark.
there is almost no difference in energy density or 'bang per volume' as u put it between different octane ratings. the octane rating is basically how fast the fuel burns compared to 100% octane. 91 octane burns faster and is more unstable than 98, hence more susceptable to detonation.

[Tim.]

Haha! These topics are always good for a laugh.

[sbv]

...So for a JDM B4/GTB which would normally get 100ron in Japan, would you make do with 98 or fill it with 100 in the knowledge that it may not like the ethanol and will drink like a v8?

 

As for the 95v98 debate for a NA 2.5 - I have never found a noticeable different in driveability/performance between to 2 on any of my EJ25's, so I'd suggest the cheaper option (though I almost always filled up with 98 anyway... - do what I say, not what I do)

[Tim.]

...So for a JDM B4/GTB which would normally get 100ron in Japan, would you make do with 98 or fill it with 100 in the knowledge that it may not like the ethanol and will drink like a v8?

I used BP Ultimate 98 until i got it tuned. Didn't ping in summer on the stock JDM tune.

[allpaw4]

I ran ultimate in my RX, usually got slightly better consumption than 91 (averaged about half a litre per hundred better). Did not give better power from what I could gather, but better economy. I would normally get an extra 50km or so from a tank.

 

All this talk about ethanol is not great. MOST subaru fuel systems are not designed or rated to run even e5, let alone e10. This has been covered before. There is a government website showing the suitablility of fuel types for various vehicles I linked in another ethanol thread. Only late model NA subarus are ok for up to e10, everything else (inc. all turbo models) are NOT SUITABLE.

 

Ethanol will damage your fuel system over time. You can run it if you want, but expect problems when using it for extended periods. Ethanol aggressively attacks certain types of metals, vastly speeding up the corrosion rate. If you want to run ethanol, do the research first.

 

And yes, because ethanol has less energy per litre compared to petroleum, it does drink it more. This is why you see performance cars that run e85 generally are running 1500/2000cc injectors compared to the normal 750/850cc. Another reason not to run a tuned turbo car on ethanol fuel. That 5-10% safety margin on the injector duty cycle it was tuned with on 95/98 petrol, is out the window when you move to an ethanol fuel.