Fuel quality issues?

[Pauly]

Has anyone ever had fuel quality issues?

 

I always run BP ultimate 98 and the other day i put in shell 98. Car all of a sudden feels less power while building boost and below 4500 rpm. even on full boost until 4500 rpm it feels sluggish. Data logs show that it  is actually sluggish by looking at the intake airflow.  

 

I

[Caver]

I only ever feed her BP 98....same for my Forester.

[Jimmy]

I always use BP 98 as well.

I dont trust the super market owned brands.

[hugh]

As Kerry once told me, BP stands for 'best petrol'. BP works for me.

[GC9911]

Use Shell 95 in the MB & 98 in the P, never had a problem.

[wasserkuhl]

I have found that BP Ultimate 98 is the most consistent quality fuel to use.

 

With my Subaru RS Turbo I found that it only ran as It should on BP Ultimate. All others it seemed to be holding back and in some extreme cases it would go into limp mode.

 

Another interesting find is that with Caltex Vortex 98, I have used this fuel due to it being the only fuel for my work car.

 

I can fill it up on one tank and it wiull average 6.2L/100Km's and then the next tank it will average 7.2L/100 Km's with no discernable change to driving style or conditions. Tyre pressures are all kept correct as well.

 

I have witnessed this in no particular pattern over the last 18 months.

 

The only conclusion is that the Fuel that is coming out of the Pump is different from time to time. I am even thinking that the less efficient it is the more ethanol that is in that particular batch, even though they state that it doesn't contain ethanol.

 

Lucky I don't have to pay for it. I love BP Ultimate, but not that much!

[Pauly]

I have found that BP Ultimate 98 is the most consistent quality fuel to use.

 

With my Subaru RS Turbo I found that it only ran as It should on BP Ultimate. All others it seemed to be holding back and in some extreme cases it would go into limp mode.

 

Another interesting find is that with Caltex Vortex 98, I have used this fuel due to it being the only fuel for my work car.

 

I can fill it up on one tank and it wiull average 6.2L/100Km's and then the next tank it will average 7.2L/100 Km's with no discernable change to driving style or conditions. Tyre pressures are all kept correct as well.

 

I have witnessed this in no particular pattern over the last 18 months.

 

The only conclusion is that the Fuel that is coming out of the Pump is different from time to time. I am even thinking that the less efficient it is the more ethanol that is in that particular batch, even though they state that it doesn't contain ethanol.

 

Lucky I don't have to pay for it. I love BP Ultimate, but not that much!

 

Very interesting on your RS turbo. So you're saying it doesn't like anything else other then BP fuel?

That's exactly what mine feels like. feels like it's pulling timing in some areas. I'll let the tank drain and full back with BP and i'll report back. 

 

I've read about United fuel at some stations are contaminated with water but i've heard and read that their blend of E85 doesn't drop below 85% but is known to be over 90% at times which is a good thing IMO. I don't like caltex because i just don't.. I'd never fill up at a 7/11even though it's mobil or caltex. Shell 98 is said to be developed with Ferrari which i think is just marketing.

 

On a similar thought.. If you run caltex 98 for some reason and because the fuel was contaminated and had a lower octane reading then it should and had damaged the motor.. who is to blame? Would you contact caltex with proof that their fuel damaged your engine? 

I personally would expect them to pay for my rebuild.. and more for the inconvenience that it would have caused. 

[Pauly]

Here is what i posted on another forum...

 

 

My car has been running flawlessly after replacing the S&R sensors and the harness.. Except the miss fire at sub 3k rpm on ~ -7 in/hg which i can recreate any time i want. That's something do to with the cam and tune we assume. 

 

My issue happened on sunday night. I aways fill up my tank with 98 premium fuel from a BP fuel station. From time to time, very rarely i fill up at Shell. On sunday i needed to fill up and the closest station was shell. After driving for a while after filling up, i noticed a sluggish feel on 70+% throttle until after 4300-4500 rpm and everything else seems fine. boosts strong. torque feels flat. So i logged a 2nd gear run just to see if it isn't just me and well it's not. 

 

I did convert the log into a hp/tq graph. This way it shows me a better view of what i'm experiencing by looking at the torque curve.

 

What do you guys think? poor fuel quality?  That's the only change since.

 

yes the 1st graph done in 3rd gear and 2nd graph is 2rd gear run so that explains the lag increase. I'll get a 3rd gear run as soon as i can to confirm no extra lag. 

 

You can see the dip in the 2nd graph and the boost is flat during the dip. 

 

The colours of the graph have switched over so don't confuse yourself with the colours. I didn't realise this until now.

 

Old graph @ 18psi

 

new "issue" graph. - with added AFR to show no change in that either. @17 psi

[TINGY]

I've been into dirt bikes for quite some and a couple of years ago a motorbike magazine did a story on fuel available from normal suburban service stations.

They found that BP and Mobil had the most consistant fuel, in other words you got what they advertised, very close to 95 and 98 octane.

Performance 4 stroke motorcycle engines are very fussy and love good fuel just like our sports cars so its good to know that BP are making a good product,I too use it in all my vehicles.

[wasserkuhl]

Very interesting on your RS turbo. So you're saying it doesn't like anything else other then BP fuel?

That's exactly what mine feels like. feels like it's pulling timing in some areas. I'll let the tank drain and full back with BP and i'll report back. 

 

I've read about United fuel at some stations are contaminated with water but i've heard and read that their blend of E85 doesn't drop below 85% but is known to be over 90% at times which is a good thing IMO. I don't like caltex because i just don't.. I'd never fill up at a 7/11even though it's mobil or caltex. Shell 98 is said to be developed with Ferrari which i think is just marketing.

 

On a similar thought.. If you run caltex 98 for some reason and because the fuel was contaminated and had a lower octane reading then it should and had damaged the motor.. who is to blame? Would you contact caltex with proof that their fuel damaged your engine? 

I personally would expect them to pay for my rebuild.. and more for the inconvenience that it would have caused. 

 

Hard to prove without actual evidence, ie: samples tested etc....

 

My RS Turbo is modified and even in Standard form required 98 to perform. I tried shell, Mobil and Caltex and they all really did have some mixed results. It was definitely yanking the timing in all of them, shell in particular which sent it in limp mode so a tank drain and reset was the eventual repair.

 

I am not saying that BP is the only fuel to buy, its just the most consistent one I have used in my Cars. Thats in all my cars from my 49 Year old 356SC to my 35 Year old Carrera, my 968 CS and now even my 912(which I have had to adjust both timing and Carbs to get it to run correctly).

 

I do, however , suspect that there is some issue with what we have been getting at the pumps. I'd be annoyed if I was to put a fuel in my turbo charged car that is stated as 'no ethanol' and it actually contained ethanol as it could , as you say, damage things.

 

Still I wouldn't want to try and get compensation out of an oil company, I think I'd be out of luck.

[sydr]

A few years ago, guys on the Lotus forum ran Octane Level tests and found that not every fuel was up to its claimed octane level.  I've never used Shell since that time, and have whenever possible stuck to BP for my performance cars.  The everyday transport gets Woolworths fuels and that seems ok.  I avoid ethanol blends and am quite happy using only 98 for all my vehicles because, while for street use I don't notice any performance difference, I do find a quite marked mpg improvement.

 

But here's the thing that puzzles me.  We only have a couple of refineries, which as I understand it, produce all of our fuels.  So how is it possible that there is any difference from one brand to the next?

[JustJames]

....  We only have a couple of refineries, which as I understand it, produce all of our fuels.  So how is it possible that there is any difference from one brand to the next?

 

In a previous life I did a lot of business systems implementation work in the oil industry in S Africa.  Like Australia, and probably most places, S African oil companies distribute from each others' refineries.

 

The difference between one company's petrol and another is in the additive pack.  A BP and a Shell fuel truck will load up with "vanilla" fuel which is dosed at the gantry with the company's own additive pack.  The additive pack contains the only differences between Shell and BP's fuel.  The additive component is tiny, and consists primarily of detergent and upper cylinder lubricant.  The octane level comes from the base fuel.

 

My 0.05 is that there is likely to be more difference between individual servo's than between the different brands.  In particular, a servo that does high turnover is better for higher octane fuel because fuel loses octane as the more volatile fractions (which are the higher octane fractions) evaporate faster than the less volatile fractions.

 

Note that I am not for a second disputing anybody's experiences, just suggesting that it likely has to do with factors other than the brand of fuel involved, precisely because of the point that sydr makes, that all the servo's in an area will get their fuel from the same refinery.

[SteveT]

My 0.05 is that there is likely to be more difference between individual servo's than between the different brands.  In particular, a servo that does high turnover is better for higher octane fuel because fuel loses octane as the more volatile fractions (which are the higher octane fractions) evaporate faster than the less volatile fractions.

 

Note that I am not for a second disputing anybody's experiences, just suggesting that it likely has to do with factors other than the brand of fuel involved, precisely because of the point that sydr makes, that all the servo's in an area will get their fuel from the same refinery.

 

Just James are we then in fact better off buying our 98 octane from the Woollies servo as they have a higher turnover of product and it would be fresher and consequently higher octane? My 987 Boxster seems to run really well on some tanks and not quite as well on others and I normally buy from Woollies. They have scared everyone else out of the area long ago and I don't have a lot of options locally for fuel.

[JustJames]

@tomoaus

 

Weasel words warning:  Probably!  

 

On a vaguely related note, I'm surprised that Caltex/Woollies brand themselves as Woollies servoes instead of Caltex.  What they seem to have done is put themselves on an equal footing with 7-11 on the servo branding front.  I'd certainly  rather buy from a Caltex servo than a 7-11.

[Pauly]

Drained my tank today. I'll drive it until friday until it's completely drained and fill with BP and Log it.