Quote:
Originally Posted by dan512
I read you Bob, makes sense too, but then why does Ford recommend 20W50 an why do so many engine builders recommend heavier stuff also?
Not an easy topic I'm tackling here  |
You're right, this is not an easy subject to get a hold of. I think because
oil makers are so unwilling to give out much information regarding their products.
Ford does not always recommend a 20W-50
oil. You have to read the spec sheet that comes wiith the engine. Even for the 530hp crate engines, Ford recommends a 10W-40
oil. I glanced through a few of the Windsor motor tech sheets, and none that I looked recommended a 20W-50 oil. They all recommend a 10W-30 or 10W-40 oil.
I live in CO, it's not uncommon for my engine to see starting temps in the 20's. So I use 5W-30.
Quote:
Originally Posted by dan512
Spoke to a friend who is a mechanic and repair Porsches for a living.
He recommended Castrol TWS 10W-60. Zddp content 1000ppm.
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That's great - if you're working on a Porsche. Some Porsche's are air cooled, and have loose bearing tolerances. They need a higher viscosity. Just like an old VW or a Harley TC. You need to ask some one who works on SBF's.
Just like anything else, you have to choose the right tool for the job.
The other thing to keep in mind here is that very few of use put >10K miles a year on these cars. It's usually more like 2-3K a year. And we generally do not drive them in the winter, when it's around 0*. The cold viscosity of the oil probably really won't matter that much.
OTOH, the hot viscosity matters a lot. Follow the science, and choose wisely.