Derv supplies have two distinct brands re- Summer and Winter standard. The Winter product is dosed with an additive to stop it waxing ( freezing) and blocking the filter. It's usually effective to minus 18 degrees C. The Summer quality doesn't contain the additive which controls the CFPP ( Cold filter plugging point). As inconceivable as it may sound, when they have run out of the special additive, I have known the particular operative in charge of the Council's fuel stock, to dose a bulk Diesel tank with an amount of Petrol. Having said that I am unaware of the correct dosage ratio.
Tesco and other supermarkets buy fuel towards the end of its shelf life and add a fair bit of bio fuels too. Not a problem short term, but long term can be an issue. Get some redex, bang it in half a tank, a go give your car a bit of welly (on a safe road, of course). It'll thank you for it.
All fuel has to comply with minimum standards and I dont belive any legit petrol station is flouting those, but most of the major Brands like BP Shell Texaco etc put extras in that are claimed to have benefits - I think these are actually backed up by evidence, thats before you start on the premium brands. I got just under 200k miles out of a petrol 406 and rarely put supermarket fuel in - did the fact it was mostly Shell or Esso help - I dont know but it definitely didnt harm it
Most UK winter diesel isnt that good - the legal requirement is -10C but I think the major brands are closer to -15C - more if you put in something like V-power or Excellium ( I know French Excellium is good to -25C and the standard Total is -15C) Bunging petrol in in moderate quantities - say 10% definitely helps the waxing point but that will damage engines if done long term - as a one off its probably OK to put a gallon of unleaded in a Diesel tank but I wouldnt recommend it with modern engines. Mind thats better than a gallon of derv in a petrol tank
Two particular labs at the Shell Thornton Research Centre that I found fascinating were the Cold Start area and the Formula one area. The Cold Start area is basically a large refrigerator. Inside the room were several different makes of transit vans. The technicians were carrying out ignition performance using additive packages with their Premium brand of Derv. In a side lab, there were several graduates looking through apertures at various engines firing up. I was told they were measuring the spark gap whatever that was. In the Formula One zone, the operatives were dressed in coveralls with head visors. In that area, they were busily blending fuel for the Ferrari Formula one team which were about to compete in the Grand Prix at Monte Carlo. The day I was there, coincided with a visit by the Ferrari merchandise team. The sale was open to Shell staff, but I was given a special dispensation to make purchases for my three sons. Took full advantage and came away with three Ferrari branded hoodies, T-shirts and baseball caps which my lads loved.
Back in the 70s I was working in France and the local garage recommended adding 20% essence free derv. I did this with my Merc 220D and had no problems. However modern engines are more sophisticated so it might not be recommended today.
Of course you declared the dispensation on your Conflicts of Interest declaration lest you be accused of receiving any enticements
I did more than that TTS. I phoned my boss to ask if it was OK and showed him my receipts when I got back to work. It was fine, because we didn't have a trading relationship with Ferrari at work, so there was no enticement/ favouritism. If it had been Shell, I would have known better not to ask, because the year before a colleague at a Police Department had been censored for buying some heavily discounted Marine fuel from Shell for his boat he had moored in the Lake District. He was extremely lucky to have kept his job.
Well I’ve learned a lot about petrol and diesel today , I already knew you shouldn’t use it to get rid of moles
What a daft thing to do. Never ever put a naked flame anywhere near petroleum products. One of my mates suffered horrendous burns working on the faulty fuel system on a clients car. He'd told her to bring it in nigh on empty but she forgot and filled it up on the way in. He neglected to check unfortunately. He pulled the bung on the tank to drain what he thought was the residue and as the petrol gushed out, he stepped back onto a nearby electric fire ( it was Winter). After around five years of skin grafts and other therapies he was just about recognisable as the lad we had known before his accident.
if you've run it really low you may have pulled a bit of crap through the fuel systen and thats why its a bit jittery fill it up and give it a waz on an open road but keep your eyes on your mirrors hehe. i drive a cooper s and everyother top up up i brim it with the good stuff from tesco and i've never had any probs