Am I losing power with this oil?

[stang5]

I'm currently using amsoil asl 5w30 on my 02 Mustang GT with 7K miles on the car. Amsoil being on the thick side would I see any benefit switching to Mobil 1 5w30. I have a large stock of Mobil 1 5w30 sitting around. I'm thinking of using the Amsoil 5w30 on my 91 pathfinder with 140k miles on it. I've use amsoil 5w30 on it before and it ran quiter than the Mobil 1. thanks for any input

 

[sbc350gearhead]

Your power may increase slightly with M1.....but only a horse or two.........and then again, there may be no difference at all.

 

[darkdan]

I doubt you'd gain a hp.

I'm sure you lose more hp by drinking a glass of water before you got into the car.

 

[427Z06]

Here's one test:

http://www.carcraft.com/techarticles/15378

My guess would be none to a few at most at WOT. Greatest percentage gains come from when you're cruising at part throttle.

 

[darkdan]

So they got a 2% increase on HP by cutting their viscosity roughly in half (who knows what the cSt of that unnamed 20w50 was).

So anyone want to do the math on changing the viscosity by 10% and what amount of HP change that would be on a 260 hp (crank) motor?