For those of you with later model T&Cs (mine’s a 2006), have you used 5w-30 oil instead of the specified 5w-20? After reading way too much on this subject I decided to use 5w-30 synthetic, at least for the summer.

Your thoughts?


Gary

 

The first number refers to the base oil that is used in the oil formula. In this case it's 5WT (weight) oil and it is always 5WT oil for the life of the oil. The second number is what the copolymer chains will expand to, which thickens the oil. The second number has to do with ambient temperature range which the hot oil works at, while the first number refers to ambient cold engine starting temperatures. There are charts which explain the ambient temperature range of oils and most manuals have them. I believe the manufactures are suggesting 5W-20 because they get better pollution numbers by using lower weight oil, 5W-20 vs 5W-30.
If you live in the middle to northern US (horizontally) the 5W-30 or even 10W-30 or 40 will work just fine in the summer. If you live in the southern US then you should consider 10W-30 or 40 in the summer. Winter would be 0W, 5W, 10W depending how cold it gets down to and the second number could be 20 or 30 because you won't see the high summer temperatures in the winter.

Here are some sites which explain it in more detail:

What is oil weight.

More Than You Ever Wanted to Know About Motor Oil

What Every Motorist Should Know About Motor Oil

To answer your question, no problem to use 5W-30, especially if it's synthetic.

 

Actually it's specified because of mileage. Apparently there's a .1 mpg difference which is significant for CAFE reasons.

Most of what I read states that using 5w-20 instead of 5w-30 results in 1% better mileage and 30% shorter engine life.


Gary