so im due for change, instead of the 5w20 castrol i have been using, i want to get a heavier oil. i live in FLORIDA. should i go with a 10w20? what would be better for the seals?

I don't think you will find any 10w20.....

You would want a higher second number, this would give more protective viscosity at operating temperatures.

The first number is its 'cold' viscosity, and a 5 is probably better for quick flow to the bearings, but 10 is fine too, so a good 5w30 or even a 10w40.......

S

Florida ? use 10w40.

I live in the 407 (orlando) and just moved to 5w30 3 days ago (from 5w20 gtx) and it seems to run alittle smoother and sound alot nicer at high rev's (prob just me thinking that) but i would go for 5w30 or 10w30 i'm just not sure aobut anyting more than 30

I'ved used Mobil1 5W30 for most of my changes (34,000 miles). Recently I've started using 0W40 for topping-off. I figure it will counteract any viscosity shear-down or fuel dilution in-between changes. I usually average adding about 2 quarts or so in between changes. I also started using Marvel Mystery Oil for pre-mix several months ago, at a rate of about 250:1.

MMO is not good. It doesn't burn clean enough for the seals. It will leave a residue and build up carbon.

so im due for change, instead of the 5w20 castrol i have been using, i want to get a heavier oil. i live in FLORIDA. should i go with a 10w20? what would be better for the seals?

0-10 w 30-50

I'm on 5-30 for the first few thousand miles on my engine, then going to 40 or 50 weight. whatever I can get my hands on.

MMO is not good. It doesn't burn clean enough for the seals. It will leave a residue and build up carbon.

lots of info here does not agree with that statement..

i am not using it, but i might give it a whirl when what i use runs out.

and to the op. i ran 5 / 30 for a long time. have just gone to 10 / 40. am in orlando.

beers :beer:

Use 5-W30 Oil