I changed my lube to the 90w RP(from merc HP) a few weeks ago. I've noticed a1-2 mph increase in speed with the sme weather conditions. I've got a weak cylinder in the engine that i'm going to rectify this winter, I guess what i'm asking is the increase from the lube or is it just running better "before it blows".

A mechanic told me he had an engine on a dyno, ran 5-6 different oils through it, and the royal purple produced like 10 HP more than the others. He also felt that it breaks down sooner, and does not use it in his engines.

I highly doubt you would gain that kind of speed with a gear lube change. I've ran Amsoil in the past over Merc HP and noticed no difference in speed.

Must be the engine about to blow!

Lets test this on Jassman's new boat. We'll put Merc lube in one drive and Royal Purple in the other. Then, we run her on the limiters and see if she goes straight or turns slowly in one direction!

We've used RP for years... absolutely no problems.
It's more slippery, so less heat is generated... that may equate to slightly more HP's, but not enough for a speed gain.
Maybe the additional seat time has made you a better driver?!
Carder

I think you should try that on those ASD-7 (real surface drives for real men) that your thinking about, you will definately (gaurenteed) see a major speed increase over your present surface drives, even if you use the same gear oil in both

The satellites that run my GPS may have sped up, Who knows .

What do you think those satellites are runnng for outdrives?
Jet drives?
Carder

I checked on this for you and ALL the satellites are dialed into the Trimax drives.

As a Royal Purple distributor and avid advocate I like to think your increased performance could be attributed to the gear oil change. As the weather gets cooler the air is denser and makes more power. I disagree with the RP breaking down and I challenge that mechanic to show me proof to that effect.