Probably won't hurt a thing other than a chance at fouling a plug...and smelling like a semi truck...
In the Studebaker world, with today's crap gas, vapor lock is a big problem.
One of the tricks used a lot is to keep your old quart oil bottles and fill them with diesel fuel. Then, at fill up time, add a quart of diesel to the gas tank. The added cetane helps with pinging, and it helps prevent vapor lock. I do this all the time with my truck, as it keeps the rattle down without adding expensive octane boost.
Cheap is good.
Jeff

Quote Originally Posted by gherkin350
On the way home from work yesterday, the old girl finnaly started loosing cylinders.......sounded like an old truck with a hole in the exhaust. Most people probably thought it was a genuine ford motor
Any hoo I drained it out last night looks like I have 20 litres for the Mower now. The wife used it today and said it was just a bit smoky...hehe. I can afford a blown up mower. Since putting some high performance fuel in the Hotty, all seems to be right in the world again.
Looks llike one of those life learning curves again. They really are great!

Andy.