Premium is, as you would expect, higher quality. Some have a higher cetane number. All are cleaner for injectors and claim better lubrication qualities. Up to you whether the extra cost is worth it. I stick with the basic diesel, and add a Redex type additive every now and then (or injector cleaner). Yes I think I can feel the difference when I do this but this is highly subjective and probably just my wild imagination. Depends on how much fuel you use in a year I guess.
Totally agree about subjectivity,but it does make a difference...lol
I use eco max by Millers,and it replicates premium fuel,at a quarter of the price.
I have tried many different fuels with and without additives and the best
of the lot, smother and more mpg is bog standard Morrisons diesel, I
do like to put a dash of 2 Stroke engine oil in at about 300 to 1,
car as averaged 69.8 mph over about 95,000 miles.
Use Sainsbury’s or Costco diesel never had an issue .. put bottle of forte in tank every 5k miles and can’t say I’ve ever noticed a difference but then is that because system is reasonably clean ..qashqai not used really about town so engine gets up to temp properly
Pint of cooking oil, so it smells like Castrol R :laugh:
As with DD Bog standard Diesel & Injector cleaner once / year.
Last Petrol Scenic really hated Tesco & was better on Bog standard Shell.
Same model but newer doesn't give a ****.
Not diesel, but when I use the cheaper Tesco unleaded my car is 'lumpy' on idle, if I run it right down and fill with super unleaded, the lumpiness goes away.
Diesels even modern one do like a longish blast out of town now and then,
there's a long hill near here and when I go up it I just keep it flat to the floor
the steepness of the hill keeping speed to within the bonds of sanity.
By way of my current experiments on exactly this subject on the Scenic in my profile.
First Renault I ever owned ................. used to driver Merc/VAG/Nissan.
So no real first hand experience with the brand and control systems.
Being the a.n.a.l being I am, I have taken over the last 2 weeks to driving around with my Autel scanner permanently connected while logging/comparing what in particular "ping timing compensation":x is doing with a change from Shell 93 to 95 (recommended for the vehicle as min requirement in the fuel flap) fuel.
With this particular parameter, I have been able to see with 93 octane that huge and frequent variations in the amount of retard can be seen to occur - I reckon avg compensation around 4 degrees while max values as high as 9 degrees have been seen when really hot outside..................................................
With 95, the variation is much smaller, typically 0 degrees till the motor is quite hot, and then small variations around 1.5 to 2 degrees mark with the max so far seen of 4.2 degrees on a blistering hot day on the same roads with the same driver and the same driving style.
Cannot say I have felt any performance difference on my personal butt-dyno to be honest, but in theory any change in amount of timing must surely have an effect on the output of the engine ................. and as a result one would expect it to show somewhere if you knew when/where to look.
In a similar vein I would have to say brands could also be responsible for differences in not only performance but also durability and longevity - either real or perceived.>
Lvr have you tried Esso fuel I had a Ford that pinked on anything else.
Be interesting what your results were on that fuel.
My petrols at the moment are bikes and I honestly
cant tell the slightest difference between brands
or octane.
Can't remember the last time I saw an ESSO branded station here at all - I know they were popular in the 70-80s locally and they used to supply "drive-able" fuel. At that time though everything I owned was carb fed with distributors (eeeeeuck!) and manual initial timing set and fixed (mainly) advance curves, and because I stay at 1700m above sealevel we were more interested in 87 octane and what we could do to the engine to make them work reliably here without pinging ..................... at THAT time we even were able to buy 102 at the coast!:x
Will have to dream up a few more experiments I guess .................... >
Its that sort of anecdotal evidence that would have one believe there is or must be something to this whole thing irrespective of how insensitive we as the human evaluators are. Unfortunately one needs time and follow though to quantify what if any the gains are
I have blown an engine due to this stuff, causes the piston temps to go right up to the point of melting the piston crown and boom. One very dead stroker needing a complete rebuild, main and crank bearings/seals, piston and bore. Not cheap.
I now run all my bikes on premium, they all run better and they all return enough of an increace in mpg to minimise the extra cost.
Since the diesel put in is the main lubricant for expensive components, I avoid supermarket fuel - a Mondeo tdci I had some years ago ran dreadfully on supermarket diesel, so there must be some difference. Even if you can't notice any difference, the protection? should offer longer term reliability.
Petrol is slightly different - it can actually be worth trying cheapo vs expensive. A Proton I owned ran measurably more economically and smoother on super unleaded, whereas the Astra that followed didn't notice it at all, so I didn't waste the money!
I'm running the K9K engine in the Trojan horse I currently have on shell diesel, with a bottle of Millars, and the engine is running noticeably smoother than when I first got it. Who knows what damage the previous owner did running it on whatever was cheapest - any damage is probably done, and the car is 14 years old after all.