Which oil to use?

[Toolwise]

In the manual for my 94 Bravada, it has recommended using 5W-30 for most driving conditions. However, I believe that when I bought the car, it had 10W-30 in it, because when I changed to 5W-30, the engine got hotter, and after a time would finally drop back down one to the 200 degree mark, which was always the norm before I chanegd the oil. I have continued to use 5W-30, but after looking at my manual closer noticed that Oldsmobile gave a temp range showing 5W-30 being used in much colder temperatures, and 10W-30 being used over 0 degrees. Its about time to cvhange my oil again, and I'm wondering should i go to the 10W or stick to the 5W. Living in SoCal, I don't often see temps under 55, so it would seem 10W-30 would be the way to go, but what do you guys think?

[ericn1300]

I recomend and use 10W-40 in older, high mileage engines in warm climates. The load leveler used chevron 5w-30 on the last oil change (yes she does her own oil changes since I won't change oil anymore after the incident with the cat falling in the oil pan) and the oil consumption seems a little higher, over a half quart in 5K. It's due for another change now so we'll go back to 10w-40 and see if it helps.

[maxwedge]

Originally Posted by ericn1300

I recomend and use 10W-40 in older, high mileage engines in warm climates. The load leveler used chevron 5w-30 on the last oil change (yes she does her own oil changes since I won't change oil anymore after the incident with the cat falling in the oil pan) and the oil consumption seems a little higher, over a half quart in 5K. It's due for another change now so we'll go back to 10w-40 and see if it helps.

FYI, 10/40 is not recommended in modern high temp engines any more, I would stay away from this type of oil.

[Toolwise]

So 10W-30 is the best option for me in this warmer SoCal weather.

[Chris Stewart]

Not to disrespect Maxwedge, whose opinion I hold in high regard,
here in Tennessee for summer I use (3)10W-40 and (2)20W-50) in the '92 with 184k. When hot, in hot weather, the oil pressure drops to 20 psi stopped in traffic and in gear.
In cool weather I use all 10W-40.

The '97 w/148k gets 10W-30 year round until the hot idling in traffic pressure drops below 30 psi...about 35psi right now.

The Cummins gets 15W-40 year round.
What's your hot, in traffic, idling oil pressure Toolwise?

[ericn1300]

Originally Posted by maxwedge

FYI, 10/40 is not recommended in modern high temp engines any more, I would stay away from this type of oil.

the 4.3 is just a shortened version of the venerable cast iron 350 in spite of all the new fangeld doo dads hanging on it. also i run a 180 termostat, not exactly a high temp, high tech machine and i like it that way, but i must admit i love the fuel injection over the old quadraleak carbs.

[Chris Stewart]

Originally Posted by ericn1300

the 4.3 is just a shortened version of the venerable cast iron 350 in spite of all the new fangeld doo dads hanging on it. also i run a 180 termostat, not exactly a high temp, high tech machine and i like it that way, but i must admit i love the fuel injection over the old quadraleak carbs.

I kinda like QJets...saw one make 622hp on a 396/325 Chevy race engine on the dyno. Sounded good too

[Toolwise]

Hey, thanks for the advice guys.