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600kms From Tank


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Guest 40th-edition

Not sure how many people get 600kms from a tank. driving sensable but not like grandma..

i always was getting around 450-480 with v-power(ulp98)

but i decided to try united boost98 (has ethonal)

i found no pinging at all (pinged on v-power a little) and much larger than normal fuel economy.

just thought i would see if any one else has had same results?

cheers, azza

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Not sure how many people get 600kms from a tank. driving sensable but not like grandma..

i always was getting around 450-480 with v-power(ulp98)

but i decided to try united boost98 (has ethonal)

i found no pinging at all (pinged on v-power a little) and much larger than normal fuel economy.

just thought i would see if any one else has had same results?

cheers, azza

far out man r u sure its a factory tank? and wat kinda mods do u have?

i cannot see why a different octane rating would yield different economy? i would love for someone to show me how ?

best ive got in my r33 pfc was 550k's to a tank, and it wasn't empty

premium has a slightly higher heating value than regular and, thus can provide slightly better fuel economy.

The main reason for high octane fuel is that its actually more difficult to ignite which reduces the risk of pre detonation. So really the only reason that anyone should by premium is to ensure they dont get detonation. Not in false hopes they will gain large amounts of fuel economy as the difference between the premium and regular is very small..

as i thought, so if i was to use penis fuel and back out IGN timing vs using normal 98 ron i should see the same economy right ?

assuming all things equal, lets say plonk the car on a dyno for 550ks

back to back, one penis fuel with -5 iGN timing to take out detonation and the other normal timing back and 98ron

as i thought, so if i was to use penis fuel and back out IGN timing vs using normal 98 ron i should see the same economy right ?

assuming all things equal, lets say plonk the car on a dyno for 550ks

back to back, one penis fuel with -5 iGN timing to take out detonation and the other normal timing back and 98ron

I wouldnt expect to see any difference between the two within a couple of percent. But alot of peoples minds will tell them differently when driving on the road but there are to many variables that will affect economy to do an accurate fill up with one then the other road test with traffic, highway driving vs local ect ect.

Theoretically ethanol blends such as Boost 98 (10%) have less energy content per litre than a typical 98 RON fuel. A 10% blend has an impact on fuel economy from around 1-5%, with 3% being the average and the loss can be minimised with advancing the ignition timing but you won't get it all back. So I'm surprised you gain so much. You sure your last tank didn't involve some freeway driving?

as i thought, so if i was to use penis fuel and back out IGN timing vs using normal 98 ron i should see the same economy right ?

I would've thought you'd get worse economy if you pulled out 5 degrees timing.

Cheers

He wasn't saying that it would increase economy but if you were to test the fuel's in a performance engine so it wouldnt pre detonate during the test with the lower octane fuel

I know he wasn't saying it would increase economy. He was asking if he backed off the timing everywhere -5 degrees and ran a lower octane fuel would he get the same economy? I say no. That's why I don't run low octane fuels on a long trip - if I back off the timing say 5 degrees across the board to prevent detonation my responce and fuel economy will suffer.

If we could run say 110 octane fuel everyday and run more timing you should get better fuel economy. It won't be a big gain in economy but a gain so just like you said - you will see a marginal increase in economy. I wouldn't say though that you will see 50 - 100k's difference between 98 and 100 octane fuel - it most likely will be what you said - 3-5% - hardly noticable.

If you run afr's of 16:1 and put in more timing and drive sensibly I'd say you'd see 100 k's increase in fuel economy.

I'm happy enough with 550 k's I get from my tank highway only.

Cheers

As stated above, United Boost98 is an E10 fuel (10%) ethanol. You should not be seeing any more km per tank due to lower energy.

Ethanol in fuel will boost RON, but won't do much to the MON of a fuel at all. RON controls low speed, high load engine activity, whereas MON controls high speed, low load engine activity.

Either way you look at it, ethanol based fuels with the same RON will be an 'inferior' fuel and i'm not willing to use it in my engine. Vpower 100RON may be an exception, due to it being VPower98 with ethanol to boost RON to 100 as far as I am aware.

Fixxxer

I think the point with high octane fuel is being able to run more advance timing so that we can light the fire at a point in the cycle where the heat (thermal expansion) energy can give the greatest benefit to us per unit of fuel .

A "throttled" engine such as petrol fuelled one ends up with a reasonably low effective or dynamic compression ratio so there is a large benefit from lighting the mixture earlier before top dead centre to give the burning mixture time to develop its highest cylinder pressure when the piston is not too far past TDC . The trouble is that the air fuel mix wants to auto ignite because it is exposed to hot piston crown/valves/ chamber and reaches fire point before the plug arcs or before the spark ignited fuel and air is all burnt . Normally the last defence against detonation is to light the mixture closer to TDC because the power drop is preferable to piston (or whatever) damage .

The only performance you'd get from less that allowable timing with high octance fuel is the lighter wallet power to weight ratio .

Cheers A .

the big thing is driving conditions. i don't do very much highway driving (i class highway driving as 80kmh and above, as you can generally go more than a few kms without stopping). i do purely around town driving. i live about 3kms from work, its a mix of 50kmh and 60kmh zones, and i have to about 4 times in that distance.

if you live in the city and get a good run to work a few days of the week, instead of having to stop at every set of lights, you are going to get better economy than the next week where you have to stop every time.

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