Tesco super unleaded - a cautionary tale

MuvverRussia

MuvverRussia

MuvverRussia

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Filled my car (2009 Mazda 3 MPS) with fuel today after the gym and went to Tesco (Cardiff - St Mellons as it's nearby to the gym I use) for 45 litres of their 99 RON Super Unleaded.

Car ran OK for about 2 miles after this until it started running rough, not pulling well and essentially became undriveable in anything other than 3rd.

Managed to nurse the car home and called out the AA. Upon telling him that I'd filled up from Tesco he immediately suspected the fuel (I was the 2nd person he had seen today with dodgy Tesco fuel). Connecting a scanner to the car showed up fault codes that the engine was running lean, backing up this hypothesis. He suggested octane boost and keep on brimming the tank with VPower.

I chucked 3 bottles of octane boost into the tank and the car started running a little better. Took it out for a 100 or so mile drive and the check engine light came on (as the car still wasn't running 100% right). I figured the CEL was due to the dodgy fuel so kept on running, using up 1/3 of the tank. Then brimmed the tank with VPower and added another bottle of octane boost.

Got the car home, disconnected battery negative to clear check engine light and went out for another drive. Car now drives fine although will continue to brim the tank to water down the crap fuel.

Perhaps I was unlucky. I have never had a problem with Tesco 99 RON fuel before (when I had a remapped 1.8T Octavia vRS). Maybe it was a bad batch / old / contaminated fuel? Know I've been bitten by this experience and it's VPower only for me now (wherever possible).
 
I never had a problem when running my Focus RS mk2 on Momentum for over a year.

Bad batch or something else wrong with your car.
 
I've always used Tesco fuel, in a bike and the car, granted mainly unleaded, occasionally super in the bike, and have never really had a problem, the fuel would have to be catastrophically off to make the car run lean
 
I don't buy the "old fuel" thing personally. You would not believe how quickly petrol stations get through the stuff.
I used to work in a petrol station in a very quiet village in Wales and we went through 2-3 tankers a week. They come direct from the refinery....

EDIT
You don't really get "bad batches" either - this is the petrochemical industry, the quality control is superb.
 
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The car is booked in at Mazda next week for some warranty stuff to be done so will get them to check it out then at the same time.

It just seems a little coincidental that this occurred 2 miles or so after filling up the tank (from pretty much empty to full). I was always of the thought that as long as fuel was X octane then it would be OK.

Tesco station is a small one which is a little out of the way (and in a **** area so perhaps they don't shift much of the SUL).
 
Lopéz said:
You don't really get "bad batches" either - this is the petrochemical industry, the quality control is superb.
Click to expand...

Not issues with bad batches, but we've had several issues locally.

Two being cracked fuel tanks leaving the fuel contaminated with water at two separate petrol stations!

I don't think the fundamental issue is Momentum in the OP's case - it could be any number of things including his car or contaminated fuel.

The fact you say the car started better immediately after adding octane boost seems to suggest that any effect you saw from that was placebo.

My VXR, ST and Clio have all seen a lot (almost exclusive use, in fact) of T99/Momentum without issue.
 
Been running Tesco 99 RON on my Cayman S since June last year, and it hasn't missed a beat. Add another year or so before that for my supercharged Civic Type-R. Again, no issues.
 
Just sounds like bad fuel to me, if it was a problem with the car then after the fuel was mostly replaced and the ECU reset the problem would have come back. Besides you being the 2nd person so far that day that had called the AA out with that problem after filling up at that Tesco's who's car was reporting fuelling issues kinda screams its an issue with fuel from that station.

The was a Shell garage round here that had a fiasco after water got into the tanks, problems with the fuel can happen at any petrol station not just Tescos.
 
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MikeHiow said:
Two being cracked fuel tanks leaving the fuel contaminated with water at two separate petrol stations!
Click to expand...

That's pretty significant, environmentally speaking - surprised it didn't make the national news.

How did the water get in but no fuel get out? Petrol station tanks are double skinned and generally more than up to the job, are there serious landslip issues at the site?
 
Isn't V power ethanol free, where as Tesco99 is 10% ethanol. I wonder if that's what has caused it.
 
GeX - yep it contains ethanol.

I've never had a problem with Tesco 99 RON until now (apart from slightly less MPG than V Power), used it on my Octavia and it was always fine. Thinking it was a bad batch but will keep an eye on the car now and see what happens.
 
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