VP U4.2 ?

[avdigigeek]

Anybody see any decent gains from VP U4.2  ?

thanks in advance
Smiley 

[123user]

I think its better in almost every way compared to U4.  No gooey mess, much less stinky.  I've had more problems with my fuel line quick connectors with it, but other that, its great.

I didn't see much power difference between the U4 and U4.2 on the dyno, maybe 1/4 hp average in an unscientific study.  The octane rating on the 4.2 is a little higher than U4.  If you have a stock compression twin, I don't think the extra cost is worth it.  If you're over 12:1 compression there are gains to be had, somewhere in the neighborhood of 2.5-3% over pump gas in my dyno pulls.  I don't have any experience with this fuel in the 4-cylinders.  I'm guessing, that's where VP makes their grand claims.

I will testify to the MR- series fuels.  MR9 is awsome, but costs about $30/gallon.