Premium Diesel

patman99

'Fifth Gear' did do a lab test on BP Ultimate and Shell V-Power against their regular diesel.

They used their Citreon C5 camera car and between each test, drained the fuel out of the system and changed the feul filter.

Their tests proved that the higher-spec diesel produced 5% more power on the dyno than regular.

As an aside, I used to read a custom car mag and they did a test on the real octane rating of both unleaded and super unleaded fuels.
Their lab test showed that with the 95 RON ratted fuels, 4 out of the 5 branded fuels tested were actually below 90 RON and the 1 that wasn't was till only 92 RON.

Marktheshark

Zandoni wrote: »

Extra MPG is great but I'm also interested in the cleaning properties of the diesel.

I doubt you will get either.

Iceweasel

Weird_Nev wrote: »

I agree totally. Pretty much every modern ECU has knock sensors and will retard the ignition as soon as they sense knock. And higher RON is more knock resistant.

Grab a decent high revving Petrol engine and try it, you can actually tell the difference. My impreza ran like a dog on 95 to the point you didn't want to rev it out.

RON has a huge amount to do with power, either in a high performance engine or when mapping. There's a reason you use E85 if you want huge power from a tuned turbo.

With regards to the diesel... sorry, it's a diesel. If you're concerned with MPG, drive it frugally. Personally I think that high quality fuels and the additives are worth having, but the premium price of the posh stuff is never offset by increased MPG in my experience.

What does 'sorry it's a diesel' mean?

Ever tried an Audi R8 Quattro TDI or a BMW Alpina D3?

Slow? Smelly? Noisy? Not all diesels are tractors.

Marktheshark

Iceweasel wrote: »

What does 'sorry it's a diesel' mean?

Ever tried an Audi R8 Quattro TDI or a BMW Alpina D3?

Slow? Smelly? Noisy? Not all diesels are tractors.

Or the coppers when they scream past your Scooby at 155 in a BMW 330d M3, thats with the limiter still on, you can bet your worth its disabled on the traffic cars.

force_ten

I have no scientific tests or experience to bring to the party but i found that running a diesel car on esso supreme diesel saw nearly a 10% increase in MPG and the extra detergents and additives in the supreme diesel had to be doing some good cleaning the crap that burning diesel produces

so if you get a 10% increase in MPG and some benefit form a cleaner motor then it must be good

at work we have been told never to put premium fuel in any of the company vehicles using a company fuel card if we do it could potentially lead to a disciplinary, but i think this is purely a cost thing

BeenThroughItAll

Marktheshark wrote: »

Or the coppers when they scream past your Scooby at 155 in a BMW 330d M3, thats with the limiter still on, you can bet your worth its disabled on the traffic cars.

Yeah... It isn't.

SeduLOUs

We have a 54 plate Mondeo 2.0 TDCI, and don't notice any difference so don't normally use premium.

It did fail an MOT once on emissions though, but passed after they added something to the fuel, so we now shove a tank full of premium through it leading up to MOT and it has gotten through fine for the last 3 years.

It's never changed the MPG reading, but I've not actually bothered to properly calculate it myself. I suspect one tankful wouldn't have much of an effect anyway, and the car is already close to it's last legs having done well over 200k miles now.

almillar

BMW 330d M3

Tell me more about this mystical vehicle...
Let's not do the petrol Octane discussion here again, this thread's about diesel in some unknown car that the OP seems to want kept a secret.

Zandoni

almillar wrote: »

Tell me more about this mystical vehicle...
Let's not do the petrol Octane discussion here again, this thread's about diesel in some unknown car that the OP seems to want kept a secret.

I didn't see any reason to say what car I have but if you really need to know its a BMW 320D.

force_ten

Zandoni wrote: »

I didn't see any reason to say what car I have but if you really need to know its a BMW 320D.

he wasn't asking about your car, he was asking marktheshark to elaborate about the mythical M3 diesel a car which doesn't exist yet but looking at the way BMW are going may be made at some time in the future