bad fuel

[ald1717]

whats everyones experiences getting a bad fuel fill, i am under the assumption now that the pump that ive used for fuel the last 2 times isnt great as the car was running fine until i used this one, 5 mpg worse and car struggles to pull thought it was the octane booster but filled from same pump without and if anything it runs worse, everything was fine until i used this particular pump so i dont think its a coincidence, but would feel better if others have had the same symptoms with bad fuel.

Also want to know is it just the length of time the fuel sits that makes it bad or is it contamination ?

[Jons1001]

I only use Tesco momentum 99 and the mpg i get is pretty much always the same

[DBXdarkangel]

I watched vicki butler on fish gear re run yesterday and she tested a 12 plate golf gti with asda fuel and esso higher Ron fuel. She said there was not a massive difference.

Don't be a sheep.

[ald1717]

i remenber that test, but super unleded makes a big difference in tuned turbo cars, i know from switching from 95 to 97, you pay about £3.50 per tank more but get an extra 50 miles from it so you get the extra performance and cleaner fuel for free basically.
i was just curious if anyone others had got bad fuel in the past and see their mpg and performance dip as a result,

[LC5F]

Unleaded does go off, but it needs to have sat months and months - but I would say this is unlikely to have hapened after last year with fuel shortages pretty much emptying the tanks.

On the higher octane fuels, I was previously only using supermarket premium 97 ron - but intrigued by a thread on here I tried tesco momentum in the run up to christmas last year.
Mine isn't remapped, but it does have clean injectors and clean intake - on momentum I can definitely feel a better throttle response - it's not night and day, just more urgency.
Fuel consumption also improved at least 0.5 of a mile per litre too - so the plan is to stick with using momentum.

[ald1717]

sadly here in northern ireland the best we can get is bp 97, which on my previous fill up runs worse than tesco 95, but the week before i used the same bp station but a different pump and car was flying,
my car is mapped though with a 3in downpipe, 200 cel, and oversized ramair, so the sensitivity to octane is much more noticable. i did notice the pump lugging a bit on a few occasions whilst filling up which could be a sign of the bottom of the tank,

[deltawing]

Best to stick with esso 99 or shell 99, my car is more responsive on it and has better economy.

When e10 first came i filled up to try it and it caused a misfire, a new coil sorted it though

[ald1717]

we only get 97 here, i think it was your coil causing misfirs not the e10 fuel,
i had the exact issue last year filled with petrol and the second i left the station it was misfiring a running on 3 cylinders, assumed it was bad fuel and pulled the fuel but it was coil and just coincidence that it happened after filling up

[JoshB]

I’ve got a Stage 2 GTi and I filled up with “normal” fuel the other week as I was doing a couple of motorway runs and it was way down on power. Only a couple of times I went to round something on the A1 and the pull had gone.

Not in this car but I once filled up at Sainsbury’s in a 1.6 Zetec Focus (hire care) and it started bunny hopping after 10’s of miles and the economy dropped 10mpg. Filled up at Shell next and it returned to normal.
There were rumours at the time of them watering it down!

[ald1717]

the worst petrol i ever got was from sainsburys 2 months ago, i had just installed new injectors and did a carbon clean, and wondered why the car felt so slow,  when the tank got near empty i was nowhere near a 97 pump so i just used 95 and the car suddenly came alive, 
thinking about getting my car tuned on 95 so the hit when you get bad fuel isnt as severe,