[blueosprey90]

In the United States we have been running with E10 (leadfree) for quite a few years. In the early years E10 seemed to do quite a bit of damage, especially for boats, where it seemed to attack fiberglass fuel tanks and rubber hoses and bits. That seems to be behind us.

The biggest concern now seems to be water building up in the fuel system, and the fuel itself becoming "unstable" over time, although I'm not sure exactly what that means - perhaps fuel separation. I use a product called Sta-Bil in my fuel system during winter storage and keep the fuel tank at "full" for winter storage, both so that condensation doesn't build up in the tank. I notice a bit of crud on the bottom of my SU float bowls that looks like rust; and clean that out periodically. Otherwise, I don't think there are discernable negative effects. But if you have a decrepit fuel tank, you should expect rust to form up in there, so add a fuel filter as necessary.

I've been running the E10 in both my 59 MGA race car and in my 57 Volvo PV 444.

For the "lead free part", if that's your concern, the only thing you might want to do is to watch for exhaust valve recession in the head; and if/when that occurs, to have a machine shop install hardened exhaust valve seats. Apparently the "lead free" fuel runs hotter and can cause valve recession. But I think you need to put some miles on the car before that will occur.

On my MGA, I monitor exhaust gas temperatures with some fairly easy to install egt probes and a dual gauge. But although I try to keep egt below 1350 degrees Farenheit at race speeds, just loping around the track at normal speeds barely gets it up to 500 degrees.