Conflicting stories, Surveys best fuels and Mixing blended Fuels with Results....

Ur 98 octanes...whos doin the best of them?
E10... Hw good is it? can it be blended with with other fuels?

i think 95 is the way to go.

I noticed a big difference going from Shell V-power 98 to Caltex Vortex 98.
A got a bit of knock with the V-power and crappier mileage, Watered down cats piss

Dunno if I can pull up knock values with my dinosaur OBD1 management but would have been interesting too see as there was certainly a big differnce there.

I am hearing the 98 caltex is the newer breed octane by surveys...??

If your engine is picky about what brand of 98 it takes, then perhaps it's not really a street engine! Just a thought, might want to back off the tune a bit. All pump fuels are subject to huge variations without notice from batch to batch, especially the ethanol varieties. Regular petrol is allowed to contain up to about 10% ethanol without declaring it on the label, which makes it essentially exactly the same as E10. E85 is allowed to contain any percentage of ethanol from 70% to 85%, so the combustion properties will vary. If you want true E85 without variation, you have to buy it in drums from speed shops.

I just stick to 98. I don't have a BP near so i just get it from 7 elevn, havn't had a problem yet (touch wood). I have tried ethanol only on my ride/mowers and they play up like and run up to shit so not game to put it in my dubs.

I noticed variation between servos and a general difference between the chains.

Order I foud for the chains from best to worst in performance and economical terms.

United
Shell
BP
all the others
*
*
*
Caltex


then I find United is a rare one around in my states but consistently good.
BP at keilor park drive to be good, BP in carlsrue to be below average. Calderpark to be a real hit and miss.

Got serious fuel contamication from there.

Shell has been consistent for me problaby cos they are around any areas where I go so I rarely get to use them but got good resualts from them.

Caltex always shit regardless from where I got it, I stay away from them now.


I found 95 to be the best performance and economy, 98 my car slows down and uses more fuel, 91 is terible for economy but runs the same as 95 interestingly.


PS my spell check doesn't work on AVD forums for some weird reason???

Your car runs slower on 98? Are you sure it isn't just smoother?
It would be unusual for higher octane to not run better in both performance and lower engine temp.

yes of course it runs slower and guzzles more, its CR isn't high enough to utilize it, simple. Its only 8.5:1 way too low for 98. Laws of thermal dynamics

why did you mention temp?

does any one here of mixin e10 with a 98 make any difference..?

shell vforce is now just the 91 with more ethanol in it to make up the octane. its what killed my last two fuel regs.
not happy. i believe they are being investigated for not labelling it as such. as a result im using only bp 95 in the bug atm till i hear otherwise.

yeah i don't use 98 so i don't kown, but i have a friend who's car suits 98. he recons united and bp, shell works ok for him and he gets slightly better milage than bp but shell is hard to find here.

we both experiance poor resaults from caltex, so does our mechanic who get people coming in with problems running, starting and crap enonomy. Investigation by the mechanic have shown a lot of its been bad fuel from caltex within the local areas of central vic and melbourne. Its just to wide spread here for it to be just one isolated caltex staion.

My local dyno shop guy told me to dyno tune the car on a brand of fuel(i choose BP 98) then always run that same fuel.
He reckons the viscosity between the brands changes
I took his word for it and now dyno and race with BP Ultimate 98.

Cheers Col

I use to av gas form my old work (had the contract to dispose of it from RAAF) and man didn't they love that. Pipes use to be grey like back in the day when we could get leaded.

Quote:

Originally posted by colin My local dyno shop guy told me to dyno tune the car on a brand of fuel(i choose BP 98) then always run that same fuel. He reckons the viscosity between the brands changes I took his word for it and now dyno and race with BP Ultimate 98. Cheers Col

I use 98 from caltex, never had a problem even when changing brands, just tune it safe, like factory ecu's.
I also have tuned the kombi on caltex e85, great fuel just treat it like alcohol, ( don't let it sit to long). I test the ethanol content from the e85 on the gold coast it's constantly 76%. I just tested the e85 from Warwick independent station and was 94%, I checked 3 times, all the same.
I try to stay away from e10 as my old T4 use to ping every time I used it, worse than 91.

I use Shell V Power 98 and BP Ultimate 98 in both my turbo Subaru's and I get consistent performance and fuel economy from both, in fact economy is virtually identical with both, this tells me both fuels are very similar.
I recently tried United 100 and both cars loved it however economy suffered quite a bit, about 10% less.
In the past I've never had great results with Caltex 98 however that was sometime ago and they may have picked up their game.

As Vlad01 mentioned a car will run best with the least amount of octane required while still avoiding knock. In saying that most 98 fuel has a better additive package to help keep internals clean, this is a selling point for me.

my thought excactly...a 50/50 blend thanku aaron!
this was the confirmation i needed as it was suggested to me...

Let us know if you how it goes if you change your tune to suit.

With a road car that is not high compression the best fuel to use is the lowest you can run without the engine pinging.
This is because the higher the octane the slower the burn in the combustion chamber.
Fast burn equals good combustion and more power. However most high comp VW engines need slower burn to stop potential pinging.
It,s a trade off with compression versus combustion burn efficiency.
I would love some day to try and tune my car with e85. A local car club member circuit races a Falcon and told me he picked up over 15% hp on the dyno changing over from unleaded to e85. Worth a good sus out.

Cheers Col

Yeah Col - a few of the hillclimb cars here switching over to E85 too, but generally having to change all lines, pumps, regs and filters.... basically anything with a rubber seal in it. (needs to be Viton I think with E85 ?)

All have been talking at least 10% power increase on the dyno, but are using about 20% more fuel than they did on 98 etc.

Most interesting is some have had big head temp drops... like a consistent 20deg cooler.

Strangely the extra power hasn't seen a lot of records being broken tho...

Quote:

Originally posted by colin He reckons the viscosity between the brands changes Cheers Col

Quote:

Originally posted by donn Quote: Originally posted by colin He reckons the viscosity between the brands changes Cheers Col Viscosity, I know about viscosity when talking about oil, but fuel? please enlighten me.

This has been interesting reading.
There was some good info in this article I came across also. You learn something new some days

http://www.popularhotrodding.com/tech/0901phr_difference_between_pump_race_ga...