Hello and Oil Recommendation

[GoDawgs]

First off since this is my first post I will say hello from Bremerton, WA. So here's the story, just bought a '93 F-150 4X4, 4.9l in-line-6, 5sp manual, 200k miles. Same owner since '94 and has been well maintained. My question is which oil should I be using? After searching around here I have narrowed it down to: Rotella T6 5W-40, Rotella 15W-40 dino, and Delo 400 15W-40. My concerns would be:

-Is 15W-40 okay to use here in the NW? We get down in the 20’s maybe a handful of nights in the winter

-Is it okay or even recommend switching to synthetic after the truck has only had dino for all of its 200k miles?

Thanks for the help and feel free to recommend other oils that might be better than these three.

 

[440Magnum]

Originally Posted By: GoDawgs
First off since this is my first post I will say hello from Bremerton, WA. So here's the story, just bought a '93 F-150 4X4, 4.9l in-line-6, 5sp manual, 200k miles. Same owner since '94 and has been well maintained. My question is which oil should I be using? After searching around here I have narrowed it down to: Rotella T6 5W-40, Rotella 15W-40 dino, and Delo 400 15W-40. My concerns would be:

-Is 15W-40 okay to use here in the NW? We get down in the 20’s maybe a handful of nights in the winter

-Is it okay or even recommend switching to synthetic after the truck has only had dino for all of its 200k miles?

Thanks for the help and feel free to recommend other oils that might be better than these three.

Its been so long since I've driven a Ford 300 straight six (and never really had one apart) that I don't remember what sort of oil pressure it runs, or what kind of oil pump drive mechanism it has. My concern with going up in weight, especially on cold start, is strain on the oil pump drive gears and intermediate shaft on engines with cam driven oil pumps. If the 300 has a stout pump drive, and/or if it has pretty low oil pressure relief setting, then a 15w40 should be no problem. Personally I'd go for the RT6 5w40- its just not that much more expensive and does have better cold flow so I wouldn't even worry about the pump drive shearing off one chilly morning like I might with a 15w40.



No issue at all going to synthetic at high mileage. Another old myth that just won't die.

 

[blue94]

T6 is thought to be a very good oil and it's not hard to find. That would be my choice.

It's fine to switch. However, if your truck has any bad seals/gaskets that have been plugged up with dino oil gunk, a good syn could clean the gunk thus leading to a leak. The syn does NOT cause the leak but it can expose leaks waiting to happen sooner.

 

[Jim_Beverlin]

I had a 1982 F150 with the 300 cid inline 6 with a 5 spd manual. These motors are legendary for longevity. I would ask the owner what he used for oil. I used 10W-30 conventional oil over the 10 years I owned the truck. The motor will outlast the body unless you live in some super dry climate like AZ or NM.

 

[Scienceman]

Nice Truck!

5w-40 or even a 10w-30 would be just fine IMO.

We want pics!!!

 

[EricF]

my dad had a 1980 F-150 I6, 4spd w/OD. (less shifting!)
I put 20w50 in it one time, for spring I put 20w50 in it.
the engine didn't like it at all. took about 10minutes for the motor to get it cycling around. I was using fram's at the time, it was also 1988 too.
But I switched it back to 10w40 and it was perfectly fine.
I forgot the miles on it, but it was a whole lot.
He offered it to me, but I had no place to put it, and 2 17gal tanks at 9mph wasn't to thrilling to a kid in college.

 

[[RT] ProjUltraZ]

i'd also try a few OCIs of 10W-30 and see how it runs

 

[bullwinkle]

I'd stick with HDEO/diesel rated oil due to the flat tappet cam (AFAIK)-that Rotella T5 10W30 from Wal-Mart looks pretty good, or even a 5W40 or 15W40 from one of the big three (Delo, Rotella, Mobil Delvac) would get it done.

 

[dnewton3]

That engine is legendary for it's long life; not unlike the old Chrysler slant-six. You can hardly kill them. (Note - as I recall, there were a couple of years where Ford experimented with plastic timing gears and they didn't work out so well; other than that, no issues whatsoever).

All that said, there is no need for extra-super-duper-special lubes. Pick any 10w-30 PCMO and drive the poo out of it. You can certainly use HDEO, but you'll NEVER see any tangible increase in longevity that you'd be able to appreciate. I know an acquaintance that has nearly 500,000 miles on his, and it still runs. Dino PCMO and the OCOD every 5k miles. As said, the body is nearly in total decay, but it's a farm-runner, and while ugly, it still runs!