Adding a friction modifier to you transmission will aggravate shifting problems. It makes it even harder for the synchros to "bite" and synchronise the gears. For cold weather shifting you will need to run a lighter grade oil. Downside is less gear tooth protection. The fix to this is to run a higher quality oil, specifically one that has low internal friction co-efficients and very high film strength, and packages designed to make synchros work while lubricating them.... As you can see the issue can quickly become very technically difficult.
So you ask: "What do you recommend?"
A: Poly-ol-ester based lubricants. I believe Redline Oil is the only company that makes this for automotive use. Very expensive but you won't be disappointed.
Regards,
Roger M
quote:
Originally posted by prtdvl:
What do you think about adding it to a manual trans. for better winter shifting?