Fuel, what are people's opinions on quality

[mb240]

Okay, so I had a recent incident with Tesco fuel, the standard 95 Octane, in that I had two misfires and it just wasn't running as smoothly as usual. The misfires went when restarted and they only happened when I kicked down.

So, I filled with V-Power which is also 95 Octane here, and the car is basically sounding and behaving ten times better, including pulling all the way to almost 110kph in 2nd gear - from rolling at 20kph, no changes at ALL when kickdown, absolutely phenomenal, all the way to 6000RPM redline and changed up at 115 I think to third.

So....I am very happy, but I have to ask does/can fuel make that much difference? I really really really notice it, yet I asked in another forum (not MB related) the response was that it (Tesco fuel) was just the same as any other.

I simply can't believe it.

What are other people's experiences? You see, if I didn't kick down and just drove around "normally" I wouldn't have noticed a thing, not putting the engine under stress. So, most people of course are driving small engined cars, fill up from supermarket and no problems, because you do not floor a Yaris and expect it to respond.

So, is Tesco selling crud? Do bad batches of petrol happen sometimes? The difference in performance and sound is quite evident. I am reading loads of conflicting reports on the net. Has anyone else with a big engine noticed a difference? Is it purely in the performance areas that the difference is?

I am genuinely stumped, although I won't be revisiting Tesco for petrol ever again. I was surprised at the "fault" but having done another 300km of aggressive use of acceleration since changing, the difference is quite remarkable.

This is bugging me quite a bit. Also, we don't get any 98RON stuff here, the highest is 97RON but only in one station that sells very little - so I am put off going there as I think low use means the petrol can get "stale" - is this true.

So, fuel then.......any opinions?

 

[Roger Jones]

I've seen enough well informed opinion and anecdotal evidence -- if not conclusive scientific proof -- to follow Honest John's advice:

http://www.honestjohn.co.uk/faq/faq.htm?id=46

and stick to Shell -- Optimax and then V-Power. He has always favoured Shell and Texaco (latterly high-octane variants of other brands too) for their additives as much as anything else.

All fuels are made from the same base stocks, which the companies freely trade with their rivals, and the difference is made when the additives (detergents, lubricants, anti-corrosion stuff) are put in at the distribution depots. That is, all fuels except Optimax and, I assume, its successor V-Power -- which have their own base stock as well as their own additives. It has been suggested that the supermarket fuels have always been light on, or even free of, additives.

One neat little anecdote, a true story: the members of a model-boat club used to swear by Optimax for its cleaning properties in their tiny engines.

All I can say is that I have never had a fuel-related problem in the six cars I have run during the past ten years. I'm running four currently, all smoothly and with emissions confirmed as being very low at MOT tests.

 

[BonzoDog]

I have now had two tanks of V-Power diesel and I notice not a jot of difference. Then again I do my best to drive in a smooth calm manner and use the kick down maybe once every two months only.
Honest John makes a good point about calling both Shell petrol and diesel, V-Power, as this could lead to confusion. This is exactly what my wife did last Saturday.

 

[Rose Chap]

I only ever use Shell V Power. When fuel prices rocketed a year or so ago I did reluctantly experiment with standard unleaded and the car lost some of its va va voom and economy didn't seem to be too good either, being a couple of mpg's less than it used to be.

Granted this wasn't exactly a scientific test, but the car did feel slower.

Given that I'm very closely acquainted with my kick down and do about 2500 miles a month, I'd have no problems recommending Shell V Power.

Worth the money in my opinion.

 

[C240Sport97]

I use Tesco 99 -- which is not available in Dublin -- which is great. It is noticeably and substantially better than Tesco standard. I have tried V Power on several ocassions and not noticed any difference to Tesco 99.

 

[BTB 500]

I use V-Power in the SL and standard Shell unleaded in the Sharan. Where I am there's little difference in price compared to the supermarkets anyway, and I don't do a lot of mileage.

 

[Satch]

Apart from the premium fuels such as Shell V power, BP Ultimate, the base fuels come from pretty much the same sources because there is huge amount of cross selling/delivery.

The additive package is crucial and that is where it gets difficult. I am informed that it added to the tanker load at the filling gantry dependent upon the customer. Now modern fuel additives are quite expensive and if you have a large Supermarket chain squeezing the supplier hard on costs do not have to be a financial genius to work out what happens next.

So base fuel stock may be much the same and meet minimum standards but in practical terms what Morrisons for example end up selling is in my experience poor stuff indeed.

 

[dagd]

I only ever use Shell V Power or BP Ultimate in my SLK, I've noticed the kickdown problem with cheaper fule.

Maybe I'm wasting my money, but I'm a low milage user (around 6K per year), so so me, the difference in cost is small and I get piece of mind.

 

[IanA2]

So, I filled with V-Power which is also 95 Octane here, QUOTE]

I suppose the Guiness is weaker too.....

 

[ceejay]

I once spent several hundred pounds trying to solve starting problems on a Volvo, it went on for months without cure until I stopped using Tesco petrol. I would only ever buy supermarket fuel in an emergency as a result.

With my E320cdi I get around 5% better mpg plus smoother running on BP Ultimate - definitely worth the extra.

 

[mb240]

I only ever use Shell V Power or BP Ultimate in my SLK, I've noticed the kickdown problem with cheaper fule.

Excellent, at least I am not going mad. It was the fact that it only happened when doing kickdown that bothered me, like it was "weak" or something, but on regular driving it was no different.

Anyway, thanks for all the replies, I will be giving supermarket petrol a miss in the future.

 

[pammy]

I've never had a problem with kickdown in Edna and it gets used several times a day Have tried the various fuels and noticed not a jot if difference - so I just get whatever is there when I need it.

I notice a big difference in economy if I'm not using the kickdown though

 

[NW_Merc]

I notice a big difference in economy if I'm not using the kickdown though

Thats your heavy right foot pammy

 

[Birdman]

The problem described - kick-down response - could be simply because the injectors weren't clean. Injector cleaner might be a cheaper alternative to V-Power etc. Around here it's about 6p/litre more than standard unleaded. Injector cleaner is about £10/pack and cured a sticky fuel gauge problem, saving me several hundred pounds on replacing two sender units while giving the injectors a clean.

 

[mb240]

I had thought of that but really didn't know what sort of stuff to buy, like do you ask the bloke in Halfords, and I didn't want to put something in that might be suspect.

Same here though (all relative isn't it), it's 6c a litre more, so around €3.50 extra on each fill, which isn't much.

DO you have any recommendations for injector cleaner? I see you are using it in an E55 - I'd be interested to know anything else you do to keep it running well also!

 

[Birdman]

DO you have any recommendations for injector cleaner? I see you are using it in an E55 - I'd be interested to know anything else you do to keep it running well also!

A year ago I put a can of Wurth injector cleaner into the tank (Forte is another recommended brand) at £8 and it did the trick. Probably no bad thing to do once a year.

The most important item imo is to change the gearbox oil & filter at least at 65,000 miles or four years. It can save a rebuild.

The 4 year service is pricey so get it done by a good independent. In fact, get an independent specialist to do everything except the minimum service requirement (an MB stamp is necessary to maintain the mobilio warranty). But check they have invested in MB diagnostic equipment and are able to take on an AMG - take a look around the workshop.

 

[Roger Jones]

I use VW's own fuel additive (part number G 001 700 03 -- you might need this because dealers seem woefully ignorant of its existence). I had cool-running problems with an Audi 100 and it cured them overnight, after repeated attention by main dealers made any impact whatsoever. I have used the stuff ever since and I thank Honest John for the original lead to it. It's particularly good at counteracting the effects of short-trip driving and it does seem to boost fuel economy too.

 

[mark.t]

get a diesel men ................ and use chip fat i do ....plenty of salt and viniger too

 

[pammy]

Thats your heavy right foot pammy

lol - I know

 

[mb240]

The 4 year service is pricey so get it done by a good independent. In fact, get an independent specialist to do everything except the minimum service requirement (an MB stamp is necessary to maintain the mobilio warranty). But check they have invested in MB diagnostic equipment and are able to take on an AMG - take a look around the workshop.

I have a good independent who used to do my W210, but I am not so sure about AMG for servicing. Certainly, when I called the dealership service centre, they said "AMG and Mercedes are all the same parts anyway, there's nothing special about them" and told me I could book it in for the next available slot in 3 weeks time. Basically, he sounded like a bit of a p***k, so I am not sure where to get it serviced, the same centre had my W210 for 4 days in, without even looking at it for a repair, and I just took it and went elsewhere they are so bad.

WOuld it be insane to drive it to Stuttgart's Mercedes World servicing and get it done there as part of a ring trip? Is that crazy? Certainly, it would be a great trip, service the car and do a few laps. Has anyone done this?