[Ralph Greene]

Originally Posted by juno

Ahhh, first, the manufacturers switched to 5w-20 mainly because of CAFE .(corporate average fuel economy). Don't let them tell you anything else. Maybe they claim some other benefits, but CAFE is the main reason for the switch.

I live in a hot climate (south Florida) so I use 5w-30 RP.

They can't void your warranty for using something other than 5w-20 as long as it is API certified. The dealer can try to tell you different, but have him show you where it says that in the Magnuson-Moss Act.

Sure it's about economy. That's where the pressure came from to develop better oils. Why not use the lightest oil possible if it does the job. I'm yet to read about a normal use oil failure from using a 5W oil (or 0W for that matter) on any web sites in any climate. And there are lots of advantages to 5w and 0W oils....from cooler running engines, cleaner running engines, faster oil pressure for less wear on startup to yes....better fuel economy.