Cheap Supermarket fuel, urban myth it's bad for your diesel car???!

DEBTMONKEY1A

Hi all. Bought a Fiesta Zetec 1.4 'climate' 5 door 2006 diesel. Well pleased with it! Salesman said the engine management warning light would more than likely come of if cheap fuel used... & to only use ' v power' or expensive similar diesel to avoid this.

Sister said same thing re: advice from the dealer on her diesel Jaguar and another mechanic said it ' might' cause an issue. On driving vehicle the twenty miles or so home it DID come on as fuel low & could only find cheapo fuel. Got the code tested....was p04040 or similar but related to the ' lambda sensor' ( whatever that is!) And also the EGR not shutting 100%. Since had these errors turned off permanently (over my head but friend of a friend is a mechanic who specialises in this apparently).

No error code.....yay!

At the fill up stage now. Just to mention NO performance bissues/smoke etc & VERY economical.

I have a litre of cetane additive to improve fuel (50ml for 50litres) ....again given by mechanic. If I use this will it help cheap fuel be 'better'????!

Any ideas/feedback would be fan as so many conflicting reports!

Also be nice to try & use Tesco 10 p off a litre lol!

Car going in BTW for full service & timing belt full kit fitting on Tuesday.

Any advice/help? Thanks!:beer:

Nilrem

Basically all fuel in the UK meets set standards, the only thing that changes are a few fractions of a percent of additives.
Any car that cannot cope with UK supermarket fuel shouldn't be on the market as it's not designed to run on an internationally agreed standard fuel mix, as our "cheapest" fuel is on a par with the best sold in some countries*, and there is no meaningful difference between the Standard sold at say Tesco and what is sold at Esso (same with the "super" versions), there is a difference between Standard and Super but unless you're running car that specifically states it needs it you don't have to worry about it (and even then check the Octane/Ron rating as our standard petroi for example would be "premium" in some countries)..

Normally the whole "oh you shouldn't use supermarket fuel" or "the problem is down to supermarket fuel" thing is because it's an easy get out for mechanics and warranty companies who either don't know exactly what has gone wrong, or are looking to avoid paying out.

Personally if I was buying any normal type of car and the salesperson told me to not use supermarket fuel I'd go somewhere else for the car, as it would be a red flag to me about how they're going to be if there is any engine related issue.

IIRC the EGR not shutting properly can be because of incomplete combustion (if you are only doing short runs that'll cause it over time as engine needs to reach full working temp for best combustion), or simply age and distance covered, whilst the LAMBDA sensor can be anything from it detecting incomplete combustion to a sensor failure or a loose/broken wire between the sensor and the ECU.


*IIRC for example our standard petrol is 95 octane, in some countries that would be"hi octane" or "high performance".

wazza99

Go slap him round the face with a wet fish.........sounds like he's staving off known issues...go carefully...

DEBTMONKEY1A

Thanks! Guy was a total tool but car now runs fan after the modifications carried out.....remapped I think? The economy is just grill, and since my pals friend has been at it it's much, much smoother, different car. I don't know much about remaps but realise online they are somewhat controversial, but got a voucher on previous car, Vauxhall Corsa 1.2.3dti 2002!) And again not really knowing what they do all I can say isbagain a different car, NEVER an issue or fault code.....nippy & very economical. Only a 10% load on the insurance & here in Pennine Yorkshire would go up urber steep hills in THIRD gear!!!!

What about this additive ( checked online & purest you can get) for Cetane, worth putting in with fuel?

Been advised a 20_30 min 80mph drive on motorway will do car wonders!

On a different bote, getting sir con fixed (new compressor/condenser thingy fitted & £29.99 gas from ATS), paid for but still a leak (looking at i 4th time Monday am).....worth getting a new pollen filter & any idea on the labour cost (approx).

Thanks.....so much help given on this forum!

Smellyonion

Cheap and expensive fuels come from the same hole in the ground from the same refineries.

Certain high performance cars benefit from high octane fuels but that doesnt apply to you.

JamoLew

In my experience, premium fuels tend to burn cleaner and more efficiently which results in slightly improved performance and economy.
I currently have a diesel which gets 2-5 extra mpg from vpower and there is a slight noticeable difference in power etc. But the fuel costs more. For a long journey of 100 miles plus it works out cost neutral.
Previously I owned a 57 plate Subaru Impreza - that ALWAYS had the good stuff unless it was an emergency fill up. Tried supermarket fuel in that once and it was very noticeable difference in performance,response and sound.
Nowadays,I use premium fuel 1 in 4 fill ups

photome

I do about 30000 miles a year in a diesel, have done for years.

Always use supermarket fuel, no problems

MovingForwards

80mph on UK motorways? Do that and expect a speeding ticket through your door.

Glad you updated your insurance company to confirm it had been remapped.

I wouldnt bother with the additive, you are spending money for no reason/benefit. Best thing is if you are only doing regular local journeys is to find a dual carriage way or motorway and go for a run once a month to give your engine time to warm up, get everything flowing and blow out the cobwebs.

Deastons

DEBTMONKEY1A wrote: »

Been advised a 20_30 min 80mph drive on motorway will do car wonders!

Will the person who advised you of this also pay your fine and take your points?

Geodark

I once filled up with supermarket fuel, and within minutes I had to get the entire tank drained and flushed - granted I had filled up my diesel engine with petrol Luckily i just lived round the corner from home so managed to get it sorted without any damage.

As for the OP's question... I have a freelander TD4 and an astra 1.7cdti both run perfectly well on sainsbury's super market fuel, but they do get a full service every year including the fuel filters.

chrisw

80 is the new 70.

Alternatively, keep to 70 but drop a gear.