EG5 on Premium Petrol

[ccmengs]

Hey guys i bought my civic at the beginning of this year, it was bone stuck apart from an aftermarket pod filter. With my lead foot, i was getting about 330-380km per full tank. The last time i filled up (was a few days ago) i filled up with premium petrol and i resetted my ecu by taking out the fuse for a couple of minutes, I heard that this resets the airflow or whatever that is responsible for fuel/air mixture and hence the engine is able to comprehend the extra air coming in thus increasing fuel efficiency.

I don't know if it's placebo or not but i felt that the car was more reponsive and had a tad more power. I also realized that i've travelled 255km and i've still got about half a tank left.

Could it possibly be that the power of premium petrol and resetting the ecu doing wonders or am i going insane here ? :p

[Jaime]

I tried normal unleaded and only got 390 k's max. Then started using BP ultimate and the first time I managed 525 k's from a tank using VTEC on two three occasions, so yes Premium petrol works wonders and BP ultimate been the best. Resetting the ecu I haven't tried so have no comment.

[ccmengs]

holy shit dude that is amazing! but yeah resetting the ecu is only required if you've modded the air intake of the engine...i think so that the ecu can 'get used' to the extra air going into the engine.

[Mr_will]

you are WRONG unless your ecu is capable of advancing the timing, you will NOT get better economy or more power

http://autorepair.about.com/od/generalinfo/a/aa060504a.htm

http://www.wanderings.net/notebook/Main/IsHighOctaneGasWorthTheMoney

http://www.helium.com/items/1331276-the-value-of-using-high-octane-fuel

http://www.carsguide.com.au/site/news-and-reviews/car-news/fuel_substitution_futile

[bennjamin]

you are WRONG unless your ecu is capable of advancing the timing, you will NOT get better economy or more power

http://autorepair.about.com/od/generalinfo/a/aa060504a.htm

http://www.wanderings.net/notebook/Main/IsHighOctaneGasWorthTheMoney

http://www.helium.com/items/1331276-the-value-of-using-high-octane-fuel

http://www.carsguide.com.au/site/news-and-reviews/car-news/fuel_substitution_futile


...but i DO get better economy with 98 octane fuel. Its a plain as day fact :)

[Mr_will]

...but i DO get better economy with 98 octane fuel. Its a plain as day fact :)


only if your car's ecu can adjust the timing accordingly.

[bossy_civic]

i use bp ultimate religiously but only get 400kms to a tank mind you my car has subs and is rollin on 18s...

[ccmengs]

i really do think that premium unleaded does give you better milage

[will13]

I havn't noticed much of a difference, i use shell regular unleaded and if i drive like a grandma for the whole tank, i get 600km from full to empty. 480-540 when i hoon around.

BP Ultimate or shell vpower doesnt seem to make any difference, maybe a touch more responsive.

I'll test it out on my next few tanks, havn't used premium stuff for a while now, but im not convinced it makes any difference for me

[xclusive_eg8]

iv advanced the timing on my d15b7 to approx 19 degrees (above what Honda quotes), fill up with vortex 98 and the car runs so smooth and well powerfull lol...

normal fuel still works, but I notice the engine is more noisy (props pinging) and not smooth...
will try BP Ultimate when im empty...gone 270km on just above half a tank already

[lithium]

only if your car's ecu can adjust the timing accordingly.

oversimplifying much? this sort of stuff goes into the 'everything i learnt about cars i learnt off google' bag

i also get 10% better mileage on a Barina SRi (admittedly not a Honda) using premium. it has not been tuned for 95/98.
there are two reasons.

1) a modern engine has knock sensors that cause the ECU to retard ignition timing on hot days to prevent detonation. high octane fuel will delay the onset of detonation and retardation hence keeping power output higher for longer. we get heaps of hot days in Oz.

note that this does not require the ECU to advance timing which is what i assume you are saying by 'adjusting timing' for higher octane fuel.

2) premium contains greater amounts of fuel system cleaner than regular. you know tank-based injector cleaner? it's present in all types of fuel at varying levels but significantly higher levels for premium.

this means that using premium long term can help clean out your fuel system in particular the injectors, the backs of the intake valves and even gumming in carb jets. you get more complete fuel burn and hence fuel economy.


in fact - the increased detergent content is a good reason to use premium even on the most ordinary passenger car. say no to carbon deposits on your engine internals! :thumbsup: