your opinions please

[Hogdigerdy Dog]

Mrs hogdigerdy and i were out for a spin this weekend and came across a garage in the forest, which, believe it or not still sells full on leaded 4*
now i know modern engines have much harder valves / seats / stems amongst other things, than engines designed for leaded fuel
but i was thinking, would it be a good idea to get your valves covered with something soft that seals nicely

i wouldn't run 4* all the time, but 2 tanks a year or 1/2 a tank mixed with un-leaded 2x a year,
good or not

discuss

[Evilchicken0]

I doubt it will make the slightest diffence - there's quite a lot of adatives in petrol these days that take the place of lead. You could probably run a theroretical higher compression before pinking but your valves are more likely to touch the pistons before you find it.

[stranglerman]

How old would that petrol be????? Haven't the fuel companies stopped making it, or is that something I've miss heard??

[rockTJ]

No, it's still available in certain places for those in the classic vehicle community. As for pinking - thats all down to octane levels of the fuel. The higher octane the more the ignition doesn't have to be retarded to run at higher revs. Modern cars have knock sensors which retard the ignition when they sense pinking so they can run on either 91/95 but run more aggresive ignition timing when running 98+

If the RON of that leaded is the same as your local unleaded then there is no advantage with using it, as Evil says there are plenty of additive in modern unleaded. Unleaded does apparently go off quicker though.

Chris

[Hogdigerdy Dog]

pretty much as i thought,
and yeah it was in the country where big old money drives big old cars

it was just a bit nostalgic seeing 4* for sale
i remember when you had the choice of 2* 3* 4* or even 5* for the big jag's and sutch
and for the 2* users they even had a great big drum of 2T oil to squirt a measure at a time in the tank and self-service was a thing of the future