Anyone used Schaeffer's race oil 5w 50 high zinc formula?

I use Schaeffer's full synthetic 9000 5w 40 diesel oil and 5w 50 race oil in other vehicles so I have both on hand and both are supposed to have good levels of ZDDP but I assume the 5w 50 race oil having high zinc and being made for the flat tap motors would have more. Race is more $$ tho.

Which should I use?

'04 D2 with 79K miles in Maryland

 

Rotella 15w40 Dino for the win, Pat!

 

Project Farm!

 

I have been using Mobil 10W40 High Mileage full synthetic for a year now and see no difference. I got it for $22/5 quart in summer, now it's $27/5qt. Still worth the higher price due to longer oil intervals.

 

I've run Rotella T6 full synthetic 5w40 in my Turner since after break in. It's affordable, great oil, has enough zinc, and the perfect weight year round. A 5w40 is the same as a 15w40 at temp, just better at cold start. 5000 mile change intervals here.

 

i've used the 9000 5w40 in my Rovers with no issues.

when i could get it cheap, i used it all the time. currently, i'm running the 7000 15w40 in my daily driver '04. i was able to get a good deal on a 5 gallon bucket. i wouldn't hesitate to use the 5w40 again. hell, if it's good enough for farm and construction equipment, then it's good enough for our dirty running V8s.

i have no experience with the 5w50 racing oil. i haven't looked at the specs but it might be higher in zinc and phosphorus. good for the engine/flat tappets/cam but not so good for the cats.

 

I stay with dino - a good quality 15-40 even the walmart brand is ok for $11-12 for a gal.

 

I'm very happy with the Mobil 1 High Mileage 10w40 using a Mobil 1 oil filter. Truck has 147k miles and runs the best that it ever has.

 

Engine design is so old switching to synthetic really isn't going to help much. I ran full synthetic in my LR3, but I stick with dino oil in any Buick based Rover V8. 10w40 at the absolute minimum, but usually good old 15w40. Back in the day with my 94 RRC I ran nothing but Valvoline Racing 20w50 and had zero issues. These engines were never designed around 5w40. It was probably designed around straight 30w oil back in the day if I had to guess.

Oil type will always be an ongoing debate, but 10w40, and 15w40 are my recommendations.

 

5w40, 10w40, and 15w40 are all the same at running temp. Why not have better cold start performance?