Best Engine Oil for 307?

[Steeveedee]

That oil pressure business. The reason I used Castrol back in those days was because I had a neighbor with a Toyota pickup with a camper on it. He'd drive from California to Wisconsin to visit family and the only oil that the engine still had decent oil pressure when he got there was Castrol.

[KQQL IT]

Best? That's a debate. But I use diesel truck oil in my junk. Mainly shell rotella 15w40
it's supposed to carry soot in the oil with their EGR systems and with my short trip traveling. It can't hurt.
And enough detergent to keep it really clean inside.

[special-K]

You know, when I had diesel trucks that's what I did. I ran Rotella T 10w40 in everything. Can't hurt running turbo diesel rated oil in an old carbureted gas engine. That way I'd always have the right oil for my money maker. It was once I had oil consumption issues in the truck that took the place of my diesel that I changed it up.

[jimijam00]

Clean and the correct weight.

[BanjoDude]

Well how about that?? The local WalMart has Castrol GTX Classic 20w50 on clearance for $3/quart, so I bought a bunch of that.

[howzzzit]

Just put a name brand 10-30 wt in it and drive.

[Steeveedee]

Originally Posted by BanjoDude

Well how about that?? The local WalMart has Castrol GTX Classic 20w50 on clearance for $3/quart, so I bought a bunch of that.

$3/quart is a steal!

[special-K]

Originally Posted by jimijam00

Clean and the correct weight.

Good answer

Originally Posted by BanjoDude

Well how about that?? The local WalMart has Castrol GTX Classic 20w50 on clearance for $3/quart, so I bought a bunch of that.

Not too shabby!

[chevmn]

Originally Posted by BanjoDude

Well how about that?? The local WalMart has Castrol GTX Classic 20w50 on clearance for $3/quart, so I bought a bunch of that.

My guess is they are getting rid of all the conventional oils at walmart. I have been buying the Supertech oils at Walmart and Traveller oils from tractor supply (both arguably as good as any you can buy, and both from Warren Distribution - likely same oil as some of the name brands), and I have noticed Walmart no longer carries conventional oil in the Supertech, so I have had to buy from TSC. I also run their diesel rated oils in my diesel tractor. I have a suspicion that it will become more difficult to find conventional oils and when you find it, price will be higher I was looking tonight and a 5 qt. jug of 10w40 conventional at TSC is about $23 locally. I use full synthetic 5w30 in a Silverado truck, and it is about 21.50 (walmart supertech). I have learned you do not always get what you pay for with oils or filters. I have a driver car with over 400,000 miles which has been using Supertech conventional, but it might be soon switching to synthetic as I am not much on paying a premium for conventional oil. I suspect I will not notice any difference.

[70cst]

This

[OregonNed]

Been pretty happy with PennGrade 1 in mine the last couple of changes

[BanjoDude]

Well so much for that! That Castrol Classic is going right back where it came from. I've never heard such a racket coming from the valve train. Goodness gracious.

[special-K]

Sorry to hear that. I wouldn't want that going on for long. But maybe run it through a few short starts from cold to warm up, some revs mixed in, then a little idle time before draining. The oil is lubrication and it may be helping clear some build up out. It could be that's why it's being clackity, freed some crud up right away. I don't know what yopu are figuring on using now, but the Rotella T suggestion is a good one. Ever see diesel engine oil not long after it's been run? It gets awful black and stinky. Looks like time to change in a couple hundred miles, yet gives excellent lubrication for all day long driving as well as short stop deliveries all day long in a turbocharged engine. That's why I run it in my '72. I run the Walmart 20w50 in my '95 Suburban that was 20 years old/122k miles when I bought it. Now 28 years old/225k. I know of company fleets run on that oil. It's good oil. It's not like Walmart makes it. They just buy/sell in volume (so cheaper) and don't want law suits, so they get it from a quality producer. The proof is in the puddin' with my experience. No hi-mile oil or any other hype. Just oil that keeps my engine happy

[BanjoDude]

I pulled the drain plug and filter and let it drain overnight. Filled it with Mobil1 5w40 Turbo at the recommendation of a friend who sells into automotive for a Mobil1 distributor. She purrs like a kitten again. Hopefully this helps the next guy.

[72c20customcamper]

Originally Posted by BanjoDude

Well so much for that! That Castrol Classic is going right back where it came from. I've never heard such a racket coming from the valve train. Goodness gracious.

This the GTX Classic 20-50 ? I wouldn’t run it in an engine when the temps are below 60 degrees .

I run 15-40 in the warm weather and 10-30 in cold (if I do)

[BanjoDude]

Originally Posted by 72c20customcamper

This the GTX Classic 20-50 ? I wouldn’t run it in an engine when the temps are below 60 degrees .

I run 15-40 in the warm weather and 10-30 in cold (if I do)

Yes sir. I took what I didn't use straight on back for a refund. The Mobil1 worked like a champ.

[67 twins]

So you had 20w50 & now you put in 5w40 why not use the 10w30 like the owners manual calls for?

[BanjoDude]

Originally Posted by 67 twins

So you had 20w50 & now you put in 5w40 why not use the 10w30 like the owners manual calls for?

Very fair question. I had a long conversation with my friend who works for Mobil and learned far more than I ever thought I wanted to know about how oil technology has evolved. Pretty interesting stuff, and I wish I'd done so to begin with - would have saved me the ill-informed Castrol expirament. The net of the conversation is that the "cling" factor (my oversimplification) of some of the synthetic formulations is far greater than dino oil, which allows the wider weight spec with superior protection. This technology was obviously not available when the manual was written, and thus would not be part of the recommendation. He said that delvac 10w30 dino oil would also work just fine, but the 5w40 turbo clings better for improved protection, particularly after sitting for longer periods as mine will in the Ohio winter. He has 4 classics and that's what he uses, and he manages a team that sells about 20m gallons of oil into auto shops, ship yards, and industrial customers for gearboxes, so I guess if it's good enough for him, it's good enough for me.

Totally fair question - hopefully that helps explain my logic. Just trying to do what's best given current technology.