SH ZDDP Zinc %? How Much Do I Need?

[landtoy80]

My 94 Land Cruiser 417,000 mi, API rating was SH. How much ZDDP or zinc would of been in the oil at that time?

I read that the US car makers wanted to lower the % of ZDDP in the to increase the life of the cats and O2's. The Japaneses car makers didn't want that to happen. Anyhow from what I read is that it has been lowered over the years.

Is there a % of zinc that I should shoot for either from an oil manufacture or from additives add to the oil from parts store based of the year that the car was manufactured?

Is there enough zinc in modern oil for older vehicles? I know that you can buy ZDDP additive but how do you know if you need more or how much more?

I usually run Rotella T6 5w40 (was Rotella T 5w40) or MoS2 10w40.
I also run Motor Oil Saver to control start up smoking.

 

[artificialist]

The newer low ZDDP oils only cause problems in high performance cams and lifters. Unless you have some custom engine build, or you have some high end muscle car, you will not have a problem.

You can keep using RT6 if you want, but you don't need to.

 

[dlundblad]

417k is quite impressive. RT6 sounds like an excellent choice for your Toyota, but since you mentioned it smokes, Id try a quality high mileage oil. Quaker State Defy has the most zinc out of all the "easy to find" high mileage oils. It is also API SL. (2004 and older.)

Wouldn't mind seeing pics of your ride though.

 

[901Memphis]

The reduction in ZDDP was balanced with increases in other additives, there's more than enough anti wear additives in an API SN oil for your vehicle. If you want higher ZDDP just to sleep easy at night look no further than Mobil 1 High Mileage 10w40 or Defy 10w40 if on a budget. Both are available at Walmart, although I hear actually finding defy 10w40 in the wild varies greatly from town to town so you might be reduced to the Mobil 1 which is excellent albeit a little more expensive than defy as it should be.

 

[landtoy80]

My motor drinks M1. When the motor was only 225,000 mi old I tried M1 and if I drive aggressively it will burn 1 qt on a tank of gas, 250+/-.

It only smokes a little on start up and even less when I use MOS. If I want no smoke at all, I run MoS2 10w40 with MOS but its too thick to run in winter. I will stick with T6 and use 2 bottles of MOS instead of 1. It holds 8qt so per the bottle I should run 2 bottles.

I tried Defy in 96 Camry 275,000 mi at the time and it still had start up smoke. Its not as bad as the Land Cruiser. It now runs on Kendal GT1 Syn blend. Last couple oil changes I have not had to add oil like I was with other brands of oils.