Originally Posted By: paulri
For what its worth, in the mid 90s, Toyota did some testing with oils that had an HTHS equal to 20 and 30 weight, and found that the 20 weight oils recorded fairly equal engine wear (this was oils with an HTHS of 2.6 and 3.1). They even threw in an oil with 2.4 HTHS and found that in most of their tests, even that oil did well. Unfortunately the text was in Japanese, but the charts showed the results.
Try this link:
https://www.beamium.com/v/ZVYVMTDM
The site takes a while to upload the next page when you click on the right arrow, but it does go from one page to the next.
Thanks! I'll give it a read once I get a moment. I've barely even had time to respond to this thread. HA!
Originally Posted By: oil_film_movies
BullittGT:
Deposit on a Bullit I see. Awesome. Best looking machine.
It does depend on the engine model. Recommended weight in the Owner's Manual is what the engineers know will pass their durability testing, and thats plenty.
The more surface area and the less loading on bearings governs how viscous the oil has to be to provide a non-zero thick oil film. So its engine design as much as anything that governs the question.
5w20 (or 0w20) is all a lot of engines need. I would go up to a 5w30 on an xw20-spec engine if towing or racing in hot weather just to be sure it doesn't thin too much.
Push the video slider to the 1:44 point to see how a 5w20 does very well in a Ford 4.6L engine:
Thanks, I had a deposit on a Performance Level 2 GT that a dealer is holding to apply to the BULLITT once the orders open. As soon as I heard that Dark Highland Green was returning I was sold.