running eth vs unleaded 91/98

[jakescicluna]

what are the advantages of running one or the other because my commodore can take both and I wanted too know the better fuel.

( VE Series II SV6 Sedan 4dr Spts Auto 6sp 3.6i [MY12.5] )

 

[_R_J_K_]

See this thread, some aspects explained a bit there: E85 conversion. | Just Commodores

For a daily petrol is going to be better, E85 was introduced to Commodores because it's a biofuel and there was a possibility it could have been cheaper at the time (it's widely used as standard fuel in countries like Brazil), I think Holden had an agreement with some petrol chain that never pulled through.

Because it's sold by petrol stations it's been priced accordingly by them so it can't compete with petrol. It will take 1.5ish times the amount of E85 to go the same distance as petrol so is pretty expensive, and you need to change your oil way more often.

 

[lout]

ethanol can handle higher compression only advantage
it is cheaper but you will use a lot more , so works out more expensive
ethanol makes greta thunburg feel happy

 

[J_D 2.0]

what are the advantages of running one or the other because my commodore can take both and I wanted too know the better fuel.

( VE Series II SV6 Sedan 4dr Spts Auto 6sp 3.6i [MY12.5] )

Do you mean E10 or E85? E10 is a ripoff as you gain nothing but 2% extra fuel consumption and the fuel isn’t discounted by 2%+ so your losing money compared to using 91 RON.

E85 can gain you a decent bit of extra horsepower but your fuel consumption will increase dramatically. Not 100% sure but I think you burn something like 30% extra with E85.

91 RON is what your car has been tuned to run on (assuming it doesn’t have an aftermarket tune) so you won’t gain much benefit by running it on 98 RON other than the extra expense of the fuel.

There can be some benefit in keeping the fuel system cleaner if you believe the adds but the expense far outweighs the benefit IMO. If you only do standard day to day driving I’d stick to using 91 RON as it’s the most cost effective option (maybe the occasional 98 RON if you want to keep the fuel system clean or do some spirited driving).

 

[J_D 2.0]

ethanol makes greta thunburg feel happy

It might make her happy but it’s a placebo effect. Making ethanol burns more oil (through farm machinery, fertiliser production etc) than just burning the damn oil in the first place!

 

[shane_3800]

I believe the OP is talking about E10.

In our old work Hilux's we tested 91 vs 98 and we got better economy on 98 and saved money.
With any modern fuel injected engine it'll creep timing up to where it see's knock then it'll keep timing around there.
So 98 compared to 91 can use a couple extra degrees of advance, wether this equates to better economy is entirley based off the engine it's self.
So you really need to test this in the car you have.

I've been running 98 in my work ute as I'm set at 12° advance and last time I ran 91 I got ping at the top end WOT. But today I decided to fill up with 91 and see how it goes and if I get any ping. I think as we're moving into winter I'll be using 91.

 

[vr304]

Nothing wrong with running 95 octane as a happy medium between 91 and 98, I run 95 in my daily

 

[losh1971]

I use 98 because 95 is more expensive or the same price.

 

[Noeleter]

The flex fuel engines can run e10 or e85 but no benefit in running e85 due to cost. E10 is cheaper than 91 per litre but will use a bit more than 91 octane. Absolutely no benefit in running 95 or 98 in a standard engine. It is just petrol company hype and will just cost more.

 

[shane_3800]

The flex fuel engines can run e10 or e85 but no benefit in running e85 due to cost. E10 is cheaper than 91 per litre but will use a bit more than 91 octane. Absolutely no benefit in running 95 or 98 in a standard engine. It is just petrol company hype and will just cost more.

Yea nah I totally dissagree. Like I have said at work we found 98 was cheaper. And like I said we put this down to the engine timing being optimal on 98.

But in saying that some engines will make more power on 91 because it burns faster.

I also pull fuel systems apart quite often and have noted cars on 98 do have a cleaner fuel system than cars run on 91 or E10.

E10 must not be run on cars with steel tanks and lines because it is hygroscopic and can cause rust to form in the system.