Motor oil weights

**jmw_man** · 05-31-09, 08:35 AM

So I went to Pep Boys to get some oil and a oil filter. A employee walked up and said, "what car?" I told him and he blurted the part number to the oil filter and then blurted the motor oil weight listed by the manufacturer's manual.

I've done my reading when I was a lot younger, the weight is associated to the viscosity at different temperatures. For the 2001 ford f150, they suggest 5w-20 which from what I've read in the past is great for colder temperatures because the oil is alot thinner. For hotter months and way down here in the south, it might be a good idea to go for a heavier weight like 10w-40. Am I wrong?

**MotoZ** · 05-31-09, 08:44 AM

Use what it says in the owners manual. There is usually a summer and a winter recommendation.

I've never seen a modern engine that uses 10W40. That thick goop is relegated to lawn mowers anymore.

**PizzaSHARK!** · 05-31-09, 08:45 AM

I use 10W30 in my Camry, but it's from 96.

**deathgodusmc** · 05-31-09, 09:10 AM

Yes 5-20 is recommended by ford cold or hot. You also have to keep in mind mileage. As the engine gets older you may have to step up to a thicker oil due to wear and tear on the engine. I run penn high mileage 10-30 but my 99 f150 has 190,000 miles on it. My 07 f150 and my 99 z28 both run royal purple 10-30. So it's more of what should the vehicle be using at the milaege it's at.

**Demonofspeed07** · 05-31-09, 09:25 AM

I've worked at a lube stop and a parts house and I put 10w-40 in my 1990 350 chevy, only because it leaks if I don't. and 10w-30 in everything else, if it's not a new car with less than 50,000 miles on it, I go with 10w-30.