What Oil Weight Should I Use In California

[Gregski]

I know I know right, wars have been started over oil questions. And yes I did do an Advanced Search on Oil and all I saw were Oil Pan and Oil Pressure posts.

So specifically in California where temps do reach above 100 in the summer and maybe one or two days of freezing each winter, what oil weight not necessarily brand should I use?

Thank you guys


FYI: I like to use cheap AutoZone oil in my cars but I change the oil and oil filter every 5,000 miles religously and have not had any issues.

1974 GMC 1500
1/2 Ton Short Bed
2WD
Manual
350 four barrel
All Stock

[79Betty]

In southers indiana it gets 95+ each year and -0 too, but i use 10-W30 without issues in my 74. My ranger gets 5-W20 but only because i've had it since new.

[Malo83]

I run 10w40 in my 83 Silverado with the 305 year round, Pennz High Mileage oil is my choice. Have 219K original miles on her

[piecesparts]

I have been using 10W30 Trop Artic oil in my engines, ever since I used to work for a small county highway department. Those rock hauling trucks had over 300,000 miles on them and the insides of them were as clean as if they were just assembled. We changed oil regularly on a 3000 mile basis and worked those engines hard. Kansas sees temps from 100+ to zero degrees and we used these trucks for hauling rock and pushing snow. Of course, being in California, you could only use it until you crossed the border into another state, then you would have to use something else. LOL

[Dead Parrot]

The oil cap on my GM 350 crate motor says 10W-30. I think the 75 owners manual had 10W-30 for most times and 10W-40 for high temp climates. Have used 10W-30 synthetic blend since installing that motor. When I started, there was only a couple dollar difference between that and the cheap stuff. Change it every time the thousands digit rolls to a 0 or 5.

[dfrank]

Any good quailty 10w-30 or 10w-40. I prefer a 10w-40. Remember though if you have a flat tappet cam you need a zddp additive. I also prefer a good dino oil like Penzzoil as I have noticed that synthetic oil's tend to burn a little more oil than standard dino oil as it is slicker than dino oil and can slip past the piston rings easier.

[rich weyand]

I use Mobil1 10W30 full synthetic with one bottle of ZDDPPlus per oil change.

Note that if your engine has oil leaks, do not use full synthetic. It will run out lots faster than dyno oil. But if the engine is tight, synthetic oil IMO is better. Slipprier.