What can you do with your 1/2 ton truck?
#53
#55
The Rotella T is excellent oil. That's what I'm running in the bike now on both sides. The only reason I'm not running it in the truck is it's the wrong viscosity. I will stop lecturing after I say that those engineers that designed the engine and know the tolerances probably are aware of what viscosity will be best.
#56
That is true of a brand new engine. After 100k miles, there isn't a bearing or ring that is close to new operating tolerances. But even new, after an engine is up to temperature, the 15/40 will flow the same as 10/30 or 10/40, but have better lubrication. The lower weight oil is the ultimate compromise for average operating temperatures, fuel economy and emissions. It is not what is necessarily best for long term engine health. When I was at Boise State in the Heavy Mechanics/Diesel program, we had a Ford engineer come and give a lecture and he actually said(when another student asked about 15/40) that if he didn't have fuel economy to worry about, he would have no concern about running heavier oil in his trucks. But again, all the engineers worry about is getting EPA certification and getting engines to last 100k miles which the lightweight oils will do. I don't really care one way or the other what people use for oil. What I care about is that I know how good 15/40 has been for all my vehicles and how I have never dropped an engine in the 20 years I've been using it.
#57
That is true of a brand new engine. After 100k miles, there isn't a bearing or ring that is close to new operating tolerances. But even new, after an engine is up to temperature, the 15/40 will flow the same as 10/30 or 10/40, but have better lubrication. The lower weight oil is the ultimate compromise for average operating temperatures, fuel economy and emissions. It is not what is necessarily best for long term engine health. When I was at Boise State in the Heavy Mechanics/Diesel program, we had a Ford engineer come and give a lecture and he actually said(when another student asked about 15/40) that if he didn't have fuel economy to worry about, he would have no concern about running heavier oil in his trucks. But again, all the engineers worry about is getting EPA certification and getting engines to last 100k miles which the lightweight oils will do. I don't really care one way or the other what people use for oil. What I care about is that I know how good 15/40 has been for all my vehicles and how I have never dropped an engine in the 20 years I've been using it.
#59
That is true of a brand new engine. After 100k miles, there isn't a bearing or ring that is close to new operating tolerances. But even new, after an engine is up to temperature, the 15/40 will flow the same as 10/30 or 10/40, but have better lubrication. The lower weight oil is the ultimate compromise for average operating temperatures, fuel economy and emissions. It is not what is necessarily best for long term engine health. When I was at Boise State in the Heavy Mechanics/Diesel program, we had a Ford engineer come and give a lecture and he actually said(when another student asked about 15/40) that if he didn't have fuel economy to worry about, he would have no concern about running heavier oil in his trucks. But again, all the engineers worry about is getting EPA certification and getting engines to last 100k miles which the lightweight oils will do. I don't really care one way or the other what people use for oil. What I care about is that I know how good 15/40 has been for all my vehicles and how I have never dropped an engine in the 20 years I've been using it.
Are you saying it is best to use 10-XX until the engine is worn out enough to warrant 15-40? How do you know when to switch without somehow measuring key tolerances as the engine ages?
#60
No. What I am saying is after X amount of miles (depends on the wear of engine-normally manufacturers engineer for a 100k average) the lightweight is less effective and the 15/40 would be much better simply for the loss of effectiveness off the rings and bearings. But the heavier oil is just as good, even on newer engines, after the engine reaches running temperatures. The only thing 15/40 would do to a newer engine (in theory) is possibly hurt fuel economy in the 3-5 minutes it takes an engine to reach operating temperatures. If we were talking about brand new trucks with low mileage, I would say to use the heaviest recommended weight oil until the warranty expires, just to be safe. But I used 15/40 on my 97 Neon, 98 Sidekick and 03 Neon from new and never had a problem with my engines. I have used nothing but 15/40 in my 98 Ram since 108k miles when I bought it, and I am up to 158k and it still hums. Not even any of the common lifter tapping 318's get.