I have 158K miles on the blazer.

What viscosity should I use, 5-30 OR 10-40?

the mechanic who worked on my exhaust manifold gasket back in 11/09 put in 10-40 but I went back to 5-30 with a napa gold oil filter.

I am in florida with HEAT! all friggin year long.....

Yes All I made it down to florida, I don't know if anyone remember me asking ALOT of questions about towing, hitches and such.

 

Being in a warm climate, you could use 10w30. I would not jump to a 40 weight oil though.

 

thx kyle.