Motor oil - What viscosity do you use?

[24tesla]

Thanks Tesla!

I bought two bottles for next oil change in my DD because I didn't know if one would be enough. Now I know!

No problem. I have a message in to Lucas as well, to see if they had ZDDP in the Oil Treatments.

[Michael_King024]

15-40 rotella in all my waggy's....i love this stuff.....but i run mobil 1 exclusivley in my impala...everything else i own gets valvoline...

[Lindel]

Up here, I use 10W30, but back home I'd bump it up to 10W40 or 20W50 depending on how much pressure the engine makes.

[GTOGreg]

0W30 on freshened older motors, 10W40 on older motors with lot of miles. 5w20 or 5w30 on newer car motors, depending on mfr specs. If it has a flat tappet cam it gets a bottle of zddp plus or Crane EOS (break-in lube). I agree with Lindel on adjusting according to pressure. Conventional wisdom is that you want about 10 psi for every 1K RPM once the engine is at operating temp. I run nothing but Mobil 1 now. I used to run Rotella 15w40 until i broke an oil pump driveshaft in my Pontiac, suspect pressure was too high. In addition they cut a lot of the Zddp out when they mandated cleaner Diesel cats (same thing with Delo)...think that was 2009 or so.

[AMC-J/20]

I don't know I have had plenty of engines that idled hot at 35-55psi only turning 600-750rpm then spike up n hold 58-70psi from 1,500rpm up to max revs . . . I don't know if transfers into the 10psi/1K-Rpm method but there were within normal spec for the engines, According to the builder backed up the engines manual.

But on the flip side I have old tired dogs that only held 15-25psi at 3K-rpm warm n idled at 5-7psi.
Mike

[FSJunkie]

Amsoil 10W40 Synthetic with extra ZDDP. Where I live we see temperatures between -10F and 100F. The average anual temperature is 50F. Most folks say I should use 10W30 but I baby a motor untill it warms up anyway. Also despite popular belief synthetic does not make your motor leak more! I had an oil leak and is didn't get any worse with synthetic! It does make the engine run smoother, have more power, and run cooler.

[AMC-J/20]

I wouldn't worry about using AMSOIL 10w-40 Premium Protection, I use the AMSOIL 20w-50 Premium Protection In my 150Ci I-4 Comanche fires up n pressures up just fine.

Been running great last winter I used the 10W-40, this winter caught me I did have time to change it and so I stayed with the 20W-50 . . .

Anywho heat/cold tends to affect synthetic oils a lot less.
Mike

[FSJunkie]

These old engines need higher viscosity oils to fill in the larger spaces in between parts. More modern engines have tighter tolerances and need lower viscosity oils. There is also a trend twards lower vis. oils (0W20) for better MPG. At what cost? Your camshaft?

[AMC-J/20]

I run 10W-40 / 20w-50 / SAE60w are the 3 grades I run in all my stuff, but most of my stuff is 20+yrs old !

Mike

[FSJunkie]

Nothing wrong with that! Older cars where better in most regards. That's why I own a FSJ as my first car.

[AMC-J/20]

Yep that is what I say too, But most look down on me for my "old junk" as they view it.

Mike

[FSJunkie]

I look around the parking lot at my high school and see several types of cars: Hopped up honda civics with 4 inch mufflers, redneck trucks 3 feet from the ground, and my Wagoneer. I have beaten those souped up hondas full of hoodlums off the line more than once. As for the redneck trucks, they have such huge tires their poor six cylinder can't hardly turn them. They don't like to admit it but my wagoneer is regarded as the coolest car out there. So I ask them: why did you buy a $5000 piece of junk Honda instead of a $2000 cool old car? They have no answer. Oldies but Goodies.

[austinaubinoe]

Yeah I was drinking some coffee this morning, outside, staring at my wagoneer. It dawned on me that I probably will never own another car that is this overbuilt or well built as this one, stock.

[1jeep]

This is just my .02. But I use to run Lube shops here in Texas for a while. I always used 20w50 in everything I had. One day the guys from Pennzoil came to the shop for a promo (they brought their backup track car). Anyways, we got to talking about engines and cars and at the time I had a 442 clone. They liked it so I started it up. We got on the subject of what oil I used and told them I put 20w50. They all but laughed. Now mind you my 455 was no joke! Stroked, cam, high rise intake, 850 holley. You get the picture. It didn?t just run, it baked! So anyways, they asked why I put 20w50 in it and I told them a story about my Monte Carlo (another day) and basically how I thought it got me home. In the end they said that running that thick of oil is only robbing power. Unless you?re running a pro series type oil pump and pushing big time power you don?t have the system to push that heavy weight oil. It ends up starving your top end, especially at star up. Plus it robs HP. The thicker the oil the harder the pump has to work to pump it. It also decreases your fuel mileage do to the strain it puts on your engine. No being young and a Castrol user, I didn?t really listen to them. Then about a year later the we had another promo and the guys from Castrol came out. This time they had John Force?s back up top fuel car. I was a kid in a candy store. I got to work on the car when it didn?t start. Bad fuel pump. Anyways, I asked them about it and they agreed. I ended up changing to 10w30. Now it did improve the MPG?s, but only by about 1.5 mpgs. But it was enough to back up their theory.

As for the zinc, when I bought my 383 from Blueprint engines they said that during the brake in period you had to run either the additive or Rotella. But after that you were ok to run what ever you wanted. They recommended 10w30, and they run flat tappet cams.

As for the multi weight oil, I run 5w30 in the Kia, and 10w30 in my V8s. The multi weight oils are great. They start up as the smaller or lower number weight and as the oil warms up changes to the heavier weight. They have a viscosity modifier in them. This is great because the lower the number the easier and faster the oil get to the critical parts of the engine (heads and cam). And it only takes a very short time for it to change to the heavier weight oil. There have been countless articles about why it?s bad to let new cars warm up. But totally disagree with them. You don?t want to just take off in any car. You need to give it time to let the oil thicken to the heavier weight before you put too much wear on it. The lower viscosity is only good for getting oil to the upper parts, but it is not thick enough to protect from engine wear.

As for the 10w40, I don?t think it matters anymore, especially if you?ve rebuilt your engine in the last 10-15 years. The materials used in the gaskets, and parts are built better now and no longer need the 40 weight. 10w30 in a perfect blend.

But that?s just me.

[AMC-J/20]

We did a flow comparison between 10w-30 valvoline vs 20w-50 amsoil.

We timed seconds to pressure up and the time to top of engine, The 20w-50 amsoil beat the 10w-30 valvoline by 15% on both tests which were ran 5 times each.

Using the same engine same day, So oil clearly made a difference synthetic flows better and faster then conv. Oil so oil type also plays a roll not just grade/weight

The whole family runs 10w-40 & 20w-50 oils has for years they got/get several 100's of thousands of miles of their vehicles I4s - V8s, They taught me vehicles can go 300K miles routinely.

I normally buy my junk used, 80-120k miles then send them on their way 150-170K miles. Only in the last batch of rigs have I desired to exceed that mileage and see what life is like above 175K miles.

So far so good the MJs lil'150 I-4 is at 197K miles and counting running 20w-50 year round even
Mike