Royal Purple 10W30 vs 20W50
 

First, let me tell you that I used the "search" already and couldn't find any solid information (perhaps I'm an idiot).

What I want to know is which people recommend is better for street driving with a lot of occasional high rpm's? Also, which is better for the engine itself (don't know if it's a matter of which is better or not). Anyone with personal experiences care to share? Please do.

Just stick with 10w30 for our Bay Area climate. To me, 20w50 should really only be used for a dedicated track car or for Phoenix type summer conditions....

I live in Cali and right now it's blazing hot at times so I use RP 20W50 and it's a great liquid! Once the year goes on and gets colder I'll switch to 10W50.

Actually I may use 10W50 for my next change to see if there's any difference, but one thing for sure there's a big good difference between RP and Redline.

-Dan

Thanks guys.

Evil - do you also use their gear oil (transmission and limited slip differential)?

I'm somewhat glad I decided to go with 20W50 for my last oil change. It's been 100+ degree temps for weeks in Houston.

I use RP diff gear oil and Redline MT-90 for tranny. I think I might go all out with RP and use it in all my fluids.

Damn fluids are bank! :mad:

-Dan

When I decided to go with Royal Purple, I asked a guy on the Big List who was both a RP employee as well as an FD owner what his recommendation was for South Florida street driving, and he said 10W30 would be perfectly fine. That's what I've used for the last couple years, and I have no complaints.

jds

I read somewhere that it's not good to switch weights of oil. Is that true?

Here it is:

But I guess if you flush the engine that wouldn't be a problem.

Edit: Okay, my 2 last posts were pointless. Sorry, it's late.

That sounds like biggest load I have ever heard. According to that load, you would always run the lightest weight, so there would be less wear on the engine components, regardless of environment.

Next time you talk to that clown, ask him why auto manufacturers recommend different weights for different climates.

mobil 1 15w50 all year long. CA, central valley...when it rains, its still hot. plus it still starts close to the same viscosity being a 15w and adds the extra bit when it warms up and the turbos start beating up the oil
okay, im not an oil KING but i think 15w50 all year long is fine. people i know also use 10w30 all year
kris

I've used 10W30 all year round (in central Texas) without much issue. I've often debate going with a heavier weight during the blazing hot summer months here ... but there isn't a real pressing need to. Like stated above, unless it's a hardcore track car ... there's really no point in going heavier.