Changing Fuel Companies

[MissR34]

Hi all here is a little scenario for you that i am currently in, last year my r34 gt put out 118 kW after putting on a stainless steel catback exhaust (it was doing 101 kW fully stock), at the time i was using bp ultimate in the car, not long after that i changed the fuel and started to use shell/coles v-power, both are premium unleaded, yesterday i got splitfire coilpack installed, before getting them put in though we did a power run to see what the car was putting out so i could then work how much kW she gained from them, low and behold the car was only doing 111 kW. i couldnt understand why it dropped 7kW in under 5 mths. anyways it has gained back that 7 kW through the spiltfire coilpacks. (when if the car was still running at 118 kW it should be sitting at 125 kW at the moment).

in the long run we came to the conclusion that because i had changed fuel companies from ultimate to v power this has had an effect on the power coming out of the car.

so has anyone else noticed a change in there power from changing fuel companies?

the thing to do now is: run down the tank of v-power currently in the car, fill up the bp ultimate end of next week, keep using ultimate for a few weeks then take the car back down to the dyno and see what happens!

[ignuz]

Alot of people say all this talk about different fuels producing different power is a bit of a myth.. I'm not entirely sure, but there is a big write up in HPI about the use of different fuels. Here's the main part of it..

The synopsis

Get a selection of high-octane pump fuels and tune the car to see which makes the best power.

Instead of simply adding a product and 'pulling' the Skyline (rb26) to see what power it makes this time we had to monitor the engine's knock level via the A'PEXi Power FC programmable management system, then optimise the tune to give the biggest result.

And the results are as follows..

BP ultimate: 223.5kW

Mobil Synergy: 220.3kW

Pump 95 Octane: 211.5kW

United Boost 98: 232.2kw ( 10% ethanol, but adds 3.5% oxygen as well as the promise of excellent knock resistance into the equation)

(sorry no v-power was tested )

The conclusion

If you want to spend the time and effort having your engine tuned to run on an ethanol-based fuel, then our testing shows that you will definately get a solid peformance result and benefit. However, bear in mind that with tuning and dyno time this whole process could cost you upwards of $500, which for some may be a small price to pay, and for others totally out of the ball park. You're also stuck with the situation of only being able to fill up at one chain of service stations, which is a serious limitation in the practicality of your car.

In this instance, the current 98-octane non-ethanol unleaded fuels still do an excellent joband make decent power. As our testing has shown, there doesn't seem to be a great deal of difference in having any particular brand loyalty, as both conventional 98 octane fuels performed in an extremely similar fashion. As for the 95 octane? The results speak for themselves.

(HPI Magazine)

So yea there are differences in which fuel you're using. Although they wouldn't be felt as much without a tune for a specific kind.

From my own experience.. Vortex makes my car fart like hell. Since then I've been switching between BP and v-Power. I've only used boost united once.. Although recently one opened up near me so I might start giving that a run a little more.

[Eug]

i think there are a few other factors (along with different fuels) you'll need to take into consideration cara.

- was it on the same dyno?

- were the dyno settings the same?

- were the intake and ambient temperatures the same/similar on both days?

i've had my car on the same dyno on the same day run back to back and can confidently say you will most likely always get a ~5kw variance each run.

yes fuel mixtures have some effect, and yes it's advised that if your car is tuned for a specific brand of fuel it's best to run that particular brand as much as possible. it is also not uncommon to have a bad batch of fuel, maybe the petrol station tanks were running low (sediments on the bottom? or whatever).

7kw is nothing to worry about, i bet the next time you run it'll be different again.

[LBR33]

I dont want to start a huge debate but BP Ultimate does most of the time produce more power compared to shell fuels in skylines

[Cubes]

I'm a little sceptical of the 95ron result.

I've played around with different fuels (ulp, pulp, 98 and 98 eth). Mobil & BP 98 are on par, 98 eth there is a small increase in power but as for ulp and pulp. They both require much reduced ignition due to high knock levels.

[LBR33]

I'm a little sceptical of the 95ron result.

I've played around with different fuels (ulp, pulp, 98 and 98 eth). Mobil & BP 98 are on par, 98 eth there is a small increase in power but as for ulp and pulp. They both require much reduced ignition due to high knock levels.

I too noticed that mobil and BP are about the same

[MissR34]

its just gonna be one of thinks that i wont know until i get the fuel into the car and give it a couple of weeks and hopefully the car will get that 7 kW back. i wanna be able to show people that n/a cars can still get a decent amount a kW, in the sense of being n/a of course.