Been working part-time in a parts store. Noticed 15w40 is very cheap compared to some oils. Fellow employee says he uses it in his older Ford (78) truck and others. It contains zinc that older engines need. He has had zero problems using it.

What say the MoPar gurus?

Yup. Shell Rotela.

And it doesn't have as much zinc in it as it use to have, so might have to use Rislone ZDDP zinc additive anyway, I do.

I use it in my 66 coronet with a poly 318, works great.

My good friend used to run it in his Camaro bracket car. Has a 436" sbc that makes about 700 hp and made a lot of passes every season running 6.0 index classes. Never had any problems with it.

I see the Rotela has a new look to the gallon jug again.

Has it been changed again?

I've been using 10-30 and 15-40 diesel-spec for many years now.

I can't get 5-30 diesel-spec anymore so I go back to Mobil 1 in the winter.

Just ask any Truck Maintenance Person when the last time it was that they used Penzoil, Amsoil, Quaker State or any of that other "flavor-of-the-month" crap in their Cat, Cummins ISX, Volvo D13 or Detroit DD15.

Check to see if it has the SN rating on it, if it does, it's got the low zinc. Shell sells their rotella in the diesel spec CK-4 which IIRC has around 1100ppm zinc and they also make a dual rated CK-4/SN which only has the 800ppm zinc.

I work at a shop that does maintenance for two transport fleets that run freightliners and volvos. Both have switched from 15w40 CK-4 to 10w30 CK-4/SN rated oils. We have trucks that run from the frigid northern wastes down to texas, florida and california on the 10w30. I used to a 15w40 fan but now I think it's a a needless waste costing you hp and fuel mileage unless you need the heavier oil.

Answer for the OP: Yes, it's been done many many times.

At my local WalMart I see three different Shell Rotellas. You have to look at the information in the circle on the back of the bottle.

Your engine's need for the zinc compound depends nearly entirely on the acceleration of the lifter by the cam lobe and the valve spring load. If you're running stock springs and a mild Chevy lobe cam, any old oil will do. Same with hydraulic roller lifters.

If you have gone along with me to cams with very fast lifter acceleration rates and high load valve springs, the oil needs to have additional anti-wear properties which usually means more zinc dialkyldithiophosphate. 1200 to 1600 ppm seems to be the right amount. Many oil companies have this information hidden on their websites. There are other posts by people who have had lab tests done.

Motorcycle oils have sufficient amounts of ZDDP, too. I don't see a price advantage, though. I fail to see a price advantage with Diesel engine oils, either.

Additives are problematic as there is a chance of reacting with the oil's own additive package.

R.

I don't recall a majpor difference in pricing between car and truck lube oils, as long as one compares like to like. Petroleum oils, blends and full synthetics are available for both engine types.

I use Rotella T4 or T6 depending if I want dino or syn oil.

Both are also JASO rated so I use T6 in my MC.

That's not entirely correct. API SN only limits phosphorus to 600-800 ppm for energy conserving grades (ie 5W-30, 10W-30, etc). A dual-rated (API CK-4/SN) 15W-40 grade of heavy duty engine oil is limited to a maximum of 1200 ppm of phosphorus. Ford WSS-M2C171-F1 specifies a minimum phosphorus level of 1000 ppm.

I've been using Petro-Canada Duron SHP 10W-30, which has both API-CK-4 and Ford WSS-M2C171-F1. Petro-Canada shows that this grade is suitable for SN because it uses the same additive package of its 15W-40 grade, which is rated CK-4/SN.