tesco diesel in d5
 

Thought I would share my recent experience with tesco diesel in our s60 d5 56 plate.
3 weeks ago car serviced. We had to travel to the west Midlands and back to Durham so my wife filled up at tesco bishop Auckland with a whopping 12p off a litre from the shopping. I had to make a 70 mile journey so reset the CPU to see if the mpg had improved post service. To my horror I averaged 34.6 on a journey that should see 40+.
Checked garage had actually changed air filter. Checked injector pipes hoses etc.
2 days later we set off for w.MIDs.
Mpg peaked at 37.8 around manc and levelled out for the rest of the motorway leg. Dropped to 37.1 at wombourne.
Topped up the remaining third of a tank with 6 gallon of shell diesel. Mpg started climbing again immediately when it had been falling on the single track roads. 200 miles home and the average had risen to 40.1. I would normally expect to see an average of 44-45 altogether.
I realise that this is hardly scientific but the gauges have proved reliable and consistent. Thought I had a problem till I topped up with shell.
Should have smelled a rat with 12p off.

Interesting you should say that, I noticed something very similar - I didn't check the MPG readout, but I used 3/4 of a tank on a journey that normally uses 1/2 tank after filling up at Tesco.

Didnt think much of it until reading your post....

S

Very interesting as I noticed mine was smoking last week after I had bought fuel in tesco, it doesnt normally smoke at all!

Don't know about their Derv but their petrol is usually crap. The 95 ron stuff is like all the other cheap 95 but the "momentum" (probably because you'll be relying on the car's momentum to keep it going) is pants. It's octane is boosted using bioethanol (giving Tesco a kickback from the government for using a part-biological fuel) an doesn't contain the same energy as Shell V-Power.
In my car (lightly modified and mapped to run 97ron or above), I don't get as much power as the Shell stuff but my MPG drops by about 4-5.

All fuels now will have to contain a certain percentage of renewable fuel.

If you have a diesel you need a cetane booster.

I run my 2.5tdi on biodiesel and add acetone which helps a lot and currently returning 42.5 mainly town driving.

Wouldn't even put Tesco fuel in my mower.

In general terms cetane boosters don't work too well AND Acetone is an absolute no go additive for any diesel or petrol fuel system. It can degrade the fuel tank sender unit and the seals inside the high pressure pump if used long term.

Bio diesel is a very good natural solvent, so the fuel system and injectors will stay clean. Alas it has a much higher flashpoint than normal diesel so is bad news if it contaminates the engine oil, as it does not evapourate off much when warm.
Pure Bio from a farm might clean well AND is an excellent lubricity additive for normal diesel, BUT that does not mean it does not get dirty.
It also has a lower gell point in winter, so most users either switch to winter diesel, or if they are far enough South just mix it 50/50 with a good winter diesel.
The other winter option is to use an anti gell (It stops wax forming in the fuel filter) fuel additive.

Just to add, I was running on fumes outside Dunbar last week and had no choice other than fill up with Asda diesel. I wasn't too happy but the car is running extremely well and I can tell no difference between the Asda smelly stuff and the expensive Shell V-Power Nitro Turbo Boost Max Power smelly stuff I usually purchase. The Asda fill up cost around £6 less.

I read an intelligent article on another forum that described some official tests done on retail fuels. All fuels met the legal requirements.
The supermarket fuels exceeded the requirements by a little, no prizes for guessing that tescons came the closest to the standard, ie exceeded it by sod all. The major brands all exceeded various measures by quite a bit.
In some cars this matters more than others, for the higher performance cars it is clear that better fuels are needed, hence the better mpgs obtained.

I noticed a big increase in performance uphill when driving an old lorry once I had filled up with esso as opposed to sainsbellys.

I never shop at tescon either, the food is largely crap

most mowers will run on very low octane petrol so it doesnt really matter all that much. The ethanol content is killing all the seals and diapragms, thats what causes the mower to conk. Have to agree though, mine only gets BP.


Now, the next can of worms - should we really be growing food crops to distill into petrol when there are people in the world going hungry ?