Speaking of which, for all we know the cab companies always use -30- weight oil, no multi-viscosity. Sacrifice a bit of FE for extended engine life.

 

Vernal, Utah, na-a-a, I wouldn't meet the residency requirements. Not the skill level either.

Homework for those interested in actually understanding things like this:
What is the oil flow path to get to a crankshaft bearing?

 

mode ≠ trend

 

I'm not sure why you're assuming that 30 weight would guarantee an engine life increase. Can you explain the thinking behind this? Are there any studies published that prove this theory?

 

Higher viscosity will result in more of the oil remaining longer where it's "put".

 

I've posted a link to this information from Bob "The Oil Man" a few times, but I think both of you could benefit from reading it, so here is the link again. Please read all the chapters because this guy knows what he's talking about! Come back swinging with the answers you find: http://www.bobistheoilguy.com/motor-oil-101/

GaryG

 

Good call Gary... Haven't finished the whole thing yet but so far I'm not finding too many surprises. It's nice to read some of the actual science behind the different grades of oil and how they are affected by the environment they are used in. Suffice to say that running 30 weight oil may have advantages in certain applications but the FEH is not one of them. I keep some around for use in my small engines and my air compressor because that's what the manufacturer recommends. I've resisted going with synthetic oils in the past because I'm pretty good about changing the oil at regular intervals. I remember reading a book by Smokey Yunick when I was a teenager and he swore by synthetics for circle track racing. I guess I'm still not 100 percent convinced that they're worth the extra money but I'm guessing I might be by the time I finish reading that very informative article.

From Bob The Oil Guy:
"I truly believe that oil is much better being too thin than too thick. Over the years we have been going to thinner and thinner oils despite hotter engines with turbos and the like. The tendency is that people figure they need a 40 grade oils but then use a 50 instead. Better thinking is that if you think you need a 40, use a 30 grade oil instead. I firmly believe this based on all I know about oils."

 

I've been convinced about synthetics for years. I believe one of the reasons my Suburban has ~5,000 miles per quart @437,000 is that I put it on Synthetics very early on. When I bought my Mustang I drove it home and changed it to synthetic oil at 8 miles. Its now at 254,000 and doing as well as the Suburban.

As to the weight of oil it depends on how the bearing is designed. In some shipboard systems the pumps have water lubricated bearings. Just depends on what the design is. One of the reasons Detroit is going to lighter & lighter oils is the reduction in internal drag due to oil viscosity and thus the higher MPG attainable.

Bob is the Oil guy is a very good source. Synthetics have much greater temperature stability and are "slipperier" since they have a very uniform molecule.

 

Surprisingly after talking about all the reasons to use synthetic, Bob then admits that he runs conventional oil in his Ford Expedition... I was surprised to read that. I don't think there's much debate that synthetics are molecularly superior to conventional oils. Bob talks a lot about the issue of cold start wear as you have mentioned earlier in this thread. I wonder if there are any issues with switching to synthetic after running conventional oil for most of the life of the vehicle? I wouldn't think so but I'll have to keep reading Bill's article to find out if there are any concerns with doing that.

 

One thing I noticed about Bob, we agree about Pennzoil 5-20W in our Fords. Hopefully, you now understand I can tell the slightest changes in MPG driving my vehicles. The first time I changed the Motorcraft 5-20W blend to Pennzoil 5-20W dino, I seen a 2mpg increase in MPG. I've experimented many times in all my Fords, and this increase is consistent across the board. This is the case with Mobil One full synthetic and dino Pennzoil also. If I was going for the World Record MPG in my FEH, I would use Pennzoil dino, but I'd change the oil every 1,500 - 2,000 miles. The synthetic or synthetic blend gives me reduced MPG, but it last for 10,000 miles with no drop in MPG. I can tell when I need to change the Pennzoil by a drop in MPG. There is no change in 10,000 miles using synthetic or synthetic blend. I use 100% synthetic Mobil One 5-20W because of start-up wear and it last the entire 10,000 miles between changes without a drop in MPG. My new '12 Focus and '11 Explorer have 10,000 mile or 12 month oil change requirements and I used Mobil One for my first oil change in the Explorer at 9,950 miles. I do all my oil changes.

GaryG