time for oil change, i live in sacrament, ca and go to mountains a bit what is a good grade oil to use; 5w-30...ect
ihave 140000 on it now

 

hello bronco,
on that 86 302 engine, i would use 10W30, im pretty sure thats what they called for on that engine, thats what i used in my old 87 mercury it had 302 and i used valvoline 10w30 all climate oil in it for 11 yrs. no problems. a lot of people say castrol is good oil too.

Frank

 

is 10w thicker?

 

yes, just a little

 

10W is slightly thicker at start-up. If you ran the two weights through your fingers you could not tell the difference between 5W & 10W. I run 10-30 Valvoline MaxLife in my '94 Bronco. Has 115,000 + miles and is doing fine. Perhaps if you had extremely cold startups, 5W may be a consideration, but with the mileage you have on the vehicle, I would recommend the 10-30W.

 

Yeah the 5W or 10W30 should work fine. You might even go with a 15W40 or even 20W50 since you have more temperature swing towards the hot side there, and your engine is a bit old/loose.

The ##W is essentially the base oil weight and will tell indicate how thick it is when it's in the can, higher is thicker. The last part of the number is how the oil will act at normal operating temperature, in effect the oil will not thin out to less than the XX weight. With your temperature swings I would guess you see a lot of near 100 and occasional below freezing. 5W30 sits at the low end of the range and may not be best for high temps and old engines. 20W50 turns to fudge below freezing but is great for summer in Calif and old engines. The 10W and 15W40 is kind of in the middle.

If your engine burns oil and or you never see a lot of below 20 temps, then a 20W50 might even be beneficial. You will loose a small bit of gas mileage with heavier oils but with your engine you would not be able to reliably measure the difference.

I have used 5W30s since 1980 in the LA area and still use it since 1991 in Portland. It seems to be a good compromise for the temperatures that I saw and see. That was in relatively fresh engines in normal driving with rare high speed fun. I also use syn so I really don't consider temperature swings anymore. I don't recommend syn in your older engine, you are past the mileage where syn saves the wear and tear.

Main thing is use a good oil that meets API SAE spec for your engine, all name brands should meet spec. And change regularly.

Good Luck,

Jim Henderson

 

I've got about 105,000 miles on my 302 and use Chevron delo 15W-40 . I would reccomend it because it has a beffeir anti wear package and If the oil causes any damage to your engine then From what I read chevron will pay for all labor and parts due to oil related damage.

If your worried about 15W-40 being to thick you can use there 10W-30. They only sell it in Gallons and you have to order if your Local auto parts doesnt stock it.

ANd be sure to use a good Oil filter also Napa Gold (Wix) or motorcraft but no frams!

 

I like my HD SAE 30w It is on the Ford recommended list. I would think driving around in the mountians would qualify as Heavy Duty driving. Unless the ambient are temp is below the recommended range.

 

Well, rotella t is a good heavy duty oil, we use it in our diesel, no problems at all, great oil. Might want a little thinner than that though, maybe 10w-30 rotella t.