fuzzy

does the performance version of diesel at either shell or bp make any difference performance wise?

The Crocodile Hunter

In the real world I'd say its unlikely.

I remember years ago i think it was performance ford doing an article testing different diesel in the same car and there was no difference power wise.

I can't remember what car they were testing it on though. Maybe on a more modern high performance diesel it might make a difference?

fuzzy

I remember test on the optimax and ultimate petrol but wasn't sure about the diesel versions. ive never had a performance diesel before so its all new to me

The Crocodile Hunter

They may well help parts of the high pressure fuel system last longer due to whatever additives they put in the stuff but for a power hike I'm not sure.

I've got a 330d that benefits from a remap, next fill up I'll try the more expensive stuff and see if i can tell any difference.

fuzzy

mine is a 3 litre turbo diesel merc. I'm going to do some runs at the 1/4 mile then its going for a remap as well then itll be more 1/4 mile runs to compare after the remap. wasn't sure if its better to remap it for the better fuel or if itll make no difference whats its set up for.

The Crocodile Hunter

Ive got no idea.

I had mine tuned by one of the most reputable bmw tuners around and they didn't mention it

burnzy

if your going for a standard "stage 1" remap then it won't matter what you fill it with for remap, I have noticed better mpg and it does feel quicker with premium diesel in cars I've owned, but it's not critical like petrol, if your going to have a rolling road print out at the end of it then fill it with premium to make the numbers look good, fill it a few days before to let it run through the engine and the ecu should adjust slightly to the better fuel in the process, Tesco momentum is supposed to be the best then shell nitro or whatever they have decided to call it now, that's certainly the case with unleaded anyway.

It's Czech Mate

Yeah, the car goes faster because your wallet will be lighter....

Fartblood

Minored on combustion fueks for my Masters.

Simplifief somewhat, the higher octane fuel actually has a lower calorific value than the 95 RON petrol, so unit for unit is actually less energetic. A few cars, modern Golf GTi's, Evo and Scoobys, high performance turbos, can advance their timing and thus increase their power output, but theyre not so much gaining any power as simply operating as intended in tje first pkace. More conventional engines will see zero performance improvement - it would be against the laws of thermodynamics to do so.

The diesel is a different kettle of fish. Diesel can not advance the ignition (although Mazda are about to launch a hybrid spark ignition/diesel unit that can) , so questions over octane don't apply. The big difference here is the additive package, which may clean the fuel system and engine internals and not so much increase power, but maintain it at its optimum.

I've yet to see any scientifically valid testing from an independent source that shows an improvement in economy or power for either of these fuels. Keep your engine in good fettle, drive it properly (particularly pertinent to diseases) and they are of no benefit.

geordiegooner

I've recently just had to sit through a 2 day course on petrol/stations ect and the trainer stated the best petrol available is the shell v power then costco premium petrol/diesel.it's all about the additives added to these fuels that make the difference but do you get extra performance off these fuels said on just using them wouldn't think so.

burnzy

well you haven't looked far, there have been quite a few test that show higher octane fuel improves performance, engines have been pulling there timing for many moons now so there is a benifit there straight away, the higher octane fuels will allow the engine to run at its intended timing for longer before the engine starts to pull it back.

diesel works on a cetane rating not octane, if I could be arsed to search I'm sure I'd find quite a few tests on premium diesel.

Fartblood

I did actually say that engines that have to retard their timing to run on 95 will run at their intended full power on 97, so I'm glad you agree. As aforementioned, that isn't an improvement in power but is simply allowing those units to operate optimally

Cetane is a critical element to consider with compression ignition, which is why I wrote "...so questions over octane don't apply.". Once again, I'm glad you agree.

Please feel free to direct me to some research which is both properly scientific and independent - you indicate there are many, yet have failed ro link to a single one. There's plenty of magazine guff, and consumer groups, TV programmes, YouTube carriers et al, but I've yet to to see any credible, properly objective scientific testing that proves any benefit. There wasn't any when I was studying the subject postgrad, and I'm not aware of any since.

fuzzy

so will the same sort of basic turbo petrol engine upgrades to air filters and exhausts to allow the engine to breath better make any difference in a diesel? the 360mm brembo discs and pads ive just bought will certainly help it to stop well in the twin piston calipers!

burnzy

What's not scientific about the testing on 5th gear? Just because it wasn't performed in a lab with people with white coats doesn't mean it isn't scientific, and your idea that people in a lab are "properly objective" is silly too as there is loads of testing data that is worked in such a way that they get the results they are often funded too.
Quite clearly a benefit, also momentum and nitro unleaded are actually 99ron and not 97ron like you assume.

fuzzy

yeah...when a boffin produces results you see whos funded the research first before buying into it.

Brendan

iTrader: (1)

I have noticed a slight increase in MPG when using Costco diesel.

geordiegooner

Main difference between costco and other cheap supermarket fuel is costco additives are added on site to the fuel where others are premixed and it's a higher Ron ect