Shell Rotella T6 15W-40?

Originally Posted by Katana29

Both, but mainly consumption. I drive long distances pretty frequently and I'd rather not carry oil around with me if I can help it.

And yeah I would have thought it is what it is with blow by, but the burn off rate was doubled with the 0w-40 compared to the 10w-40 and there's no way the properties of the oil aren't factors with such a significant change.

I only discussed the valve train noise because the thicker oil also seemed to run quieter than the thinner oil (lubricating things better).

Originally Posted by Katana29

Anyone had any experience with this?

I recently switched to running the 5w-40 T6 compared to the Mobil 1 10w-40 high mileage.

I found that it burns off significantly faster than the M1 (about a quart every 2500 miles). Valve train is also slightly nosier at highway speeds (I have aftermarket cams and the lifters tick until I get to operating temp). Normally they'd be silent but with this oil they are slightly more noticeable.

I looked up the flashpoints.

M1 10w-40 High Mileage- 239 C
T6 5w-40- 233 C
T6 15w-40- 249 C

I'm thinking the higher flashpoint will help resist burn off and partially explains what I'm seeing but I could be wrong. The motor is built with forged rods and pistons so the clearances are wider with more blow-by. I'm trying to find the best balance between oil consumption and lubrication. Temps never get above 180 with the oil cooler and the car holds an extra 1.5 quarts over stock.

I would have thought the thinner oil would have lubricated the upper parts of the engine more effectively but the slight increase in noise is leading me to believe a thicker oil is actually better for my case.

Any thoughts on this appreciated

Thanks
-James