If it's so okay to burn anything you want in your motors , then why does the manufacturer go out of there way to specify a certain weight oil ?

It's specific in the manual and even on the oil cap.. - Seams like there would be a bulletin of some kind ? I don't understand why people want to change this...

 

To meet CAFE fleet fuel economy standards. That's why, over the last decade or so, you saw MFRs change the oil requirements for engines to lighter oils. While the engines did not change internally.

There is nothing wrong with using what the MFR recommends. It's preferrable. But it's not the only "right" option...but if you are under warranty then absolutely run what the MFR specs.

A lot of guys with blown/turbo engines don't want to run such a light oil, as blowby is increased and the general feeling is that you want a slightly thicker oil in a performance motor.

Many high-output engines spec a heavier oil, or one with a huge viscosity range, like 0W-40, which requires a synthetic.

 

jbrew......thanks for the pic of the cap :santa:

 

Thanks for the explanation. I tried Amsoil once and was met with blowby for some reason ..I normally used Castrol 50/50 and switched back to that. At 211,000 miles and great compression in my 5.4L I'm sticking with it.

On another note - that Amsoil combined w/Red Lubeguard did knock my tranny temps down consideribly , I don't care much for it in the crankcase tho..

 

No problem , a little blurry - that was an accidental pic actually

Also that pic is from a 2001 5.4L motor, not the 98 motor..

 

I'd go make them change it...It isn't going to hurt your engine, no, but I would demand exactly what I pad for, but I'm a you-know-what about that kind of stuff, because if it was me, I know that the customer would go complain immediately and I'd have to change it, so I would say get what you should have got.

 

Who's to say what oil did they really used. When I worked part time at a lube place years ago a truck would pull up with bulk oil in the tanks, no brand name on the tanks just what WT oil it was. I'd say it was the cheap stuff

They had bottle oil too but you better ask for it. The only good thing is you get a free cola.

 

I recently got a great deal on a case of name brand 10w-30w motor oil, API spec SL. 5w-30w oil wasn't available.

My F-150 car repair guide specifies 5w-30w oil for my 4.6 liter engine. I suppose this is because the overhead cams and valve trains need lubrication "right now" after start up, and since they are located a good distance from the pump.

 

Your manuals need to be updated. Ford has changed the specs to 5W-20 for almost all engines back to the early/mid 90's.

 

I wish people would post the whole thing.

However, a 5w30 motor oil will be thinner than a 10w30 motor oil when subjected to the same low temperature conditions - because the "W" number is lower. This is an indication of better cold weather performance. In other words, a 5w30 flows better in cold weather than a 10w30 motor oil will. Think of the "W" as a "winter" classification instead of a "weight" classification.

Classifying the "W" Rating
Results from the Cold Crank Simulator (CCS) and Mini-Rotary Viscometer (MRV) tests are used to determine the oil's "W" grade. The better the engine "startability" of the oil at low temperature, the lower the W classification. Each W grade must meet certain "startability" requirements at a specified temperature.


I run 0W50 when I can afford it. If not I try to run at least a 5W20. Why? Because of the W rating that Ford recommends. If you keep the 5W rating or better it, use a lower number like 0, you will lessen the risk of start up damage.