He was and is 100% correct.
Thread moved from GC
I think you may be getting confused with gunge in the engine block which cannot be affected by fuel additives which only affect the combustion chamber and cylinder head.
If you use an engine flush before an oil change on an old engine you may disturb the gunge in the engine block which can get into the oil galleries and block them causing oil starvation and potential engine failure.
Some people say not to change from mineral oil to fully synthetic oil for the same reason.
That's all the "ultimate fuels" are.The normal petrol and diesel with a bit of additive in it.It costs BP less than a penny a litre extra and in return they make a fortune out of people.
In some circumstances it might not have bio either, in which case it's definitely worth a bit more.
I use cheap Tesco / Asda fuel, never had any issues in my BMW 320d M sport. Intact, never had any issues in any car in regards to fuel. Save your money for more important things.
I don't plan to use it all the time, but it has brought a marked improvement, it drives the same now as when you get your vehicle back after a service if that makes sense?
When I get a free moment next week I will need to take a look at the additives you can buy to see if they offer better value.
I get through a full tank every week 70 liters or so, so the extra 8 quid or so adds up. Haven't noticed any difference in millage so I not including that as any benefit. Equally I can't say I have noticed anymore power, but I have noticed that the occasional shudder (as though it was straining for feul) has gone. And that the engine is starting smoother and easier.
From the tests undertaken of fuel RON and comparing the supermarket forecourts with the big brand 'special' fuels (BP & Shell primarily), typically the result was that scientifically speaking, the fancy stuff was better, and had numerical evidence to prove it - but the key point was that was as the result of almost forensic analysis.
In the real world, during daily driving, the benefits are rarely noticeable (at least in so much as whatever it promises you in performance or increased mpg, is difficult to show). This appeared to be the case for both petrol and diesel fuels.
I use 99 RON from Tesco, or Shell VPower, but purely because the Golf R requires min 98 RON. From memory, VPower Nitrounleaded is 100 RON, and doesn't contain the ethanol that Tesco 99 does (it's basically 97 RON with ethanol added to bump the octane up).
As a side note, I remember watching an interesting Shell experiment where Ferrari tanked up one of the late V8 F1 cars with VPower to compare it with their race fuel. Aside from needing to run a little less ignition lead, it made nearly as much power through most of the rev range, and more power in a few places.
I know this thread is about diesels but this feature from 5th Gear showed there was some advantage to running flash petrol but ... not much in terms of performance.
The numbers at 5m27s for a VW Golf GTi
Shell V Power 240.9bhp
Esso Supreme 240.5bhp
BP Ultimate 236.7bhp
BP unleaded 236.1bhp
Asda unleaded 235.8bhp
5bhp for £5 a tank?Probably not for me.
I was advised to use the premium 1:4 full fills, never noticed any difference.
Comparing peak power figures from dyno runs isn't much of a yardstick for real world driving, but there can be advantages to using better fuel.
My current motor is a '55 Volvo D5 auto (EU3 pre DPF). In town, on a hot day, it drives like it's had a new gearbox fitted when it's full of BP ultimate as compared to supermarket fuel.