Thanks to everyone for the advice.
I seems I will go with the ULP.
The reason I asked the original question is that both my "get to work car"
and my weekender run on LRP, while the family car runs on ULP, and in
general I fill up my 2 stroke fuel when I am in one of my cars, so it was
just easier to fill the car, then throw a litre in the can at the same time,
rather than get it from a different pump, as I only get small amounts due to
the fuel going stale.
My Father, who is a mechanic said it wouldn't hurt to run LRP, but I thought
I'd do more research.
He and I had both heard stories of LRP eating through fuel lines, wrecking
seals in carbies, however he had never experienced it. LRP in old leaded
cars, and ULP in ULP cars, and you can't go wrong he said.
I know that in general ULP was brought in for purposes of the environment,
but those cars had to run a cat convertor. Leaded of course was bad for the
environment, but the purpose of lead was to lubricate the valve stems/seals.
A good sign of a nice mixture setting in a leaded car was a grey exhaust
pipe, that grey was lead deposits.
AN old trick to get a unleaded car running better was to put a tank or 2 of
leaded through. It would burn the insides of the cat convertor out, giving a
free flower exhaust, but this was illegal the ULP without a cat was actually
more detrimental environment than a leaded car.
Anyway, leaded is phased out, with LRP running a valve lubricant in place of
lead.
I have ran ULP with a valve lubricant (Flashlube) as an experiment both my
cars, but the result was underpowered and pinging, therefore ULP having a
lower octane rating, which I was told that anyway.
So I could see no harm in running LRP, but thought I would see.
My whipper (ryobi) suggests 25:1, chainsaw 40:1, and the other whipper
(stihl) 50:1, but only that when using stihl oil.
In general I stick to 25:1, same as our workplace goes with. The ryobi has
run that since I was at school when I bought it, so about 11yrs, with no
carbon buildup, and not many plug replacements. I do know running a 2 stroke
at low revs causes them to build up carbon in the exhaust port.
I may as well go with ULP, but I will check the octane ratings, and if LRP
is more on the mark than ULP I will go with that.
It was interesting that about 5yr ago I went to get pre-mixed 2 stroke at
the servo. I asked what fuel was used and it was ULP. Leaded was still
around then, ands the attendent said it was illegal for them to sell leaded
2 stroke premixed. I never asked why, but wish I did.
It was interesting about the person who replied mentioning that aircraft
fuel has a lot of lead. This I did not know, but I did know running avgas
that had a real high octane rating in car engines that weren't equipped with
hardened valve seals/seats, would burn the valves out, due to lack of
lubrication. Of course this avgas is illegal on the street, but many rally
cars/hill climb cars, and track cars use it.
Thanks again for all help.