I am constantly amazed at how much controversy such a small difference in oils can make. Why having a low first number seems so terrible to so many around here amazes me. Whats not to like? Better flowablity a protection at low startup temps, and behavior thats the same at operating temperatures. Afterall, thats what the second number means. (ie - the both behave like a 30 weight at operating temp). I'll give you that extra friction modifiers have to be used to achieve the wider spread, but beyond that???

I'm also amazed at how 5w-30 can be hard to find in places. Car manufacturers have been using and recommeding the stuff for at least ten years! My little '89 chevy cavalier has 160,000 miles on her, all with 5w-30, the recommended viscosity (Dino Oil, too). It does say 10w30 is OK when temps stay above freezing, if I remember correctly. For us up here, that rules out 6 months of the year, at least.

I had to change the oil on a trip in Colorado last year. I went into an autoparts store, and found Durablend in a 10w30. Didn't see any 5w-30. I asked at the counter and they looked at me like I was smoking crack and went on to state Valvoline didn't make 5w-30 in any grade. Needless to say, I went somewhere else...

 

I contacted two petroleum engineers and an engineer that works for a fluid analysis company we use at work (auto insurance company) for comprehensive claims.

The three agreed (independent of each other) that 5W-30 and 5W-20 can only be recommendations and that, within reason, there is no such thing as a perfect weight for every 98 F-150 4.6L XLT SCab (my vehicle). Climate, driving conditions, driving habits, etc. should all play into deciding which weight to use. The auto manufacturers provide recommendations based on CAFE requirements and general engine use/performance. Of course, going too far outside the weight recommended "might" cause problems.

When I asked about 10W-30, 5W-30, 10W-40, and 5W-20 they any would work in our climate (San Antonio), but hesitated recommending 5W-20. One hesitated recommending synthetic while the other two highly recommended synthetic (BTW, the one hesitating on the recommendation of syn. works for an offshore drilling company - hmmm).

They reminded me that engine oil is used to lubricate and therefore cool the engine (duh). It does not clean (at least it does not have nearly as many detergents as transmission fluid) as it's primary function. Therefore, if the oil is capable of providing the right amount of lubrication, then go for it.

Therefore 6 quarts of Mobil1 10W-30 for $21.00 at Costco is a good deal!

Next topic: KY or Astroglide? discuss.

P.S. Some are probably asking "Why the he!! didn't Jeff go to these guys first before adding to this already lengthy debate?" Well, neither of those guys owns an F150, or a Ford for that matter. I wanted some opinions from guys that are under the frame of a truck like mine changing the oil with their own hands and seeing what comes out after 3,000 to 5,000 miles of use.

 

Nice report jeff150.

 

Jeff, thanks for that report.

In my 02 Lightning I will be using Motorcraft 5W 20, just as Ford recommends. As long as they are backing the engine with a warranty I will follow their recommendations.

One thing that has always bothered me was after changing my oil I would start the engine at idle and have to listen to the engine clunking and cringe as I waited for the oil pressure to build. Well no longer. I now prefill my filter and crank the engine over for 15 to 20 seconds without starting the engine. This gets the oil pressure up to normal before I fire the engine. I will also do this if the truck has been sitting for any length of time before I fire the engine. I don't know if this does any good or not but I no longer have to cringe and listen to the clunking noise on startup after an oil change.

 

I've been suggesting the following for a while now. If you want to "prelube" your engine, just mash the gas pedal to the floor and crank the engine. It won't start. It's an EFI thing.

 

Dennis, you are 100% correct. That is exactly how I do it. It works and although I can't prove it, I bet it reduces wear and tear on an engine and greatly improves it's life.

 

I use 10W30 year round, synthetic, and I have never had any problems. It does make sense that someone would pre-lube their engine the way Dennis says, I may start doing that to protect more at start up. As far as I am concerned, my engine is just getting broke in at 117,500 miles!

 

I agree with Dennis use what the owners manual recommends. Mine says 5w30 oil. It really makes more sense to use 5w30 compared to 10w30. They both have the viscosity of 30 weight when warm. The 5w 30 flows better at colder temps and gets to critical engine componets sooner.