Has supermaket fuel the same quality as others?

[smithydar]

i had a customer who ran a talbot express.which he filled up with diesel from new at safeways.after sometime the injection pump failed.it was repaired by a diesel specialist and on it went.a shortwhile later same thing happened.again diesel man stripped it and it was knackered.so the customer reluctantly had a new one.ok for a while then waheey it knackered again.after this the diesel man told him to fill up from the bp garage and the vans still going now without any diesel probs.12 years later.

so you decide about that.i know who i listened to and to me it seems he was right.

it " was " all down to lubricants in the fuel...or rather lack of them.

this isnt debatable.this is what happened so i'll let everyone decide for themselves what they think.

hth in some way

darren

[Thrustyjust]

My mate,who is well known for being a bl**** good mechanic has had doubts on the fuel used,hence the thread.I guess that my new Honda diesel will take tescos finest in its stride,but just question the long term affects.Our Audi diesel has done 120k on the fuel pump and tank scavenge pump,but both were declared destroyed.The pump 'does' require lubrication from the fuel to maintain its working.He has questioned the quality of octane in petrol too,why it 'goes off' so quickly now.Our lawn mower runs super unleaded and I buy enough for 3 months or it stinks when I eventually get it running after that.My mate has also questioned common rail injector diesels,as has heard of engine damage if the injector clogs up and causes a direct fuel inject,rather than an atomised spray.

[dern]

Maybe it has contributed to the failure then... never realised fuel pumps could use the fuel for lubrication. I'm amazed that it can't take it in its stride though

[Pembroke Pat]

Oil Refineries add a number of additives to fuel eg anti static additive, lubricity additives, octane improvers etc.

Diesel needs to meet a certain lubricity as the pump and engine requires lubrication.  low sulphur diesel requires significant lubricity additives as the removal of sulphur to v low levels also removes the lubricity.

As for petrol, well it is a mix of gasolines from different refinery plant ( platformate -octane ~110, Isomerate ~80, alkylate ~100) and butane.  The butane is the most volatile and does boil off.  

But they are all made to British standards i.e. Diesel - EN590.  Sot hey should be the same in the car apart from "special" additives.

However the main dirt contaminant seems to be due to bacterial activity i.e. bugs in the fuel.  If you get water accumulating in a storage tank then you will get bugs living inthe water and eating the fuel.

I sometimes wonder how often the petrol station tanks are treated for bugs.

Pat

p.s. I work in an oil refinery in South Wales