Im running an 00 Super Cab F150 with the 4.2L V6.. Normally I put in Mobil 1 Synthetic 5W30.. Right now I got Motorcraft Synthetic Blend 5W20.. I live in Central Texas with high heat of 105-110, low heat of 30-40.. What would be a good oil to keep my truck running for a long lifespan? I have 44k miles on the block, She's changed on a regular basis.. Ive heard good/bad of both regular oil and synthetic.. I change my oil myself so cost isn't a concern.. I save a lot doing it myself.. But I'm curious as to which would be best for my truck..

 

I don't care what Ford's book says, I won't run a 5w-20 around here in the summer.

If you don't care at all about cost, keep running a brand name 5w-30 syn.

 

Ok, we have been debating back in the 4.2 forum, me and stormintexan are part of and I live in northern central indiana. It gets about high 80's low 90's for a high of summer here, on average about 80ish all summer long and in the winter can get below 0, average high is about 30ish lows overnight=teen's and single digits.

What do I run in my truck during summer?
What in the winter?
Or should I just stay the same all year around??
I use valvoline 5w20 syn. right now and i think i am going to switch to motorcraft (whatever weight is suggested). Is this ok too?

all questiions answered please, thanks to all!!!

 

Having been born and raised in Ohio (until I was 31), I can tell you that you have not seen heat like we get down here. I know that you think that it is hot when it hits 90, but I'm here to tell you, that's not hot at all. (Yes, I know, Vegas and Phoenix are even hotter, that's why I don't live there).

I would run whatever Ford recommends. If that is a 5w-20, that's what I would run. A 5w-30 is OK too.

You probably need the 5w in the winter, and the 20w is not a problem for you in the summer.

 

so what im doing, using 5w20 is ok for all year around?

 

Yep. That's what Ford recommends and sounds OK for your part of the country.

 

thanks alot!

does anyone disagree with that?

 

What about me? It gets 110-115 summer... low as 30-40 winter here.. what do ya'll recommend??

 

Stormin,

If cost is not an object, you could stay with the M1 5W-30, but with low temperatures above freezing and highs well into the 100's, I would run a good 10W-30 conventional like Chevron, Havoline or Pennzoil. I use 15W-40 Chevron Delo in similar temperatures, actually down into the 20's, but all of my "fleet" have over 100,000 miles.

Jim

 

So 5W30 isnt good for my climate? What about a 10W30 synthetic? Will that be safe for it being around 30-40 in winter and 100+ in summer?

 

I run 10w-30 in all of my gassers. 5w-30 is acceptable as well, but you really do not need the 5w part around here.

What concerns me the the 20w in the summer.

If you want to run a syn., you could consider Mobil1 5w-40 SUV & Truck oil too.

 

whats the 20W do in the summer? Explain please so I know

 

The low number is the thin number. Thin is good in winter. Oil thickens when it gets cold. The lower the number, the thinner the oil will be in the cold. This lets the oil flow better when cold (imagine trying to pump grease through your engine).

The high number is the thick number (gear oils are usually a 90-140). Thick is good in summer heat. The higher the number, the thicker the oil will be when hot, hot, hot. Thicker is better when hot because it cushions the moving parts better. Engine tolerances expand when hot, so there are bigger gaps to fill.

In 110*F heat, you want the oil to start out thick so that when it heats up, it does not thin out too much.

A 5w-20 will never be thicker than a 20w. I believe that a 20w is too thin for 110* heat and I don't care what Ford says.

A 30w is borderline, but acceptable.

As far as cold weather goes, a 5w-20 is the same as a 5w-30.

BTW, for comparison, 3 in 1 oil is about a 10w oil.

 

Just a thought. If you have a 195 degree thermostat in your cooling system, how hot do you think the coolant gets? Not trying to be sarcastic, but I believe 5W20 will be good for all normal driving conditions in any normal Earth type weather. So will 10W30 in warmer climates.
If your truck is working as designed, and driven normally then I wouldn't give it a second thought. If you tow, or off road, then an oil cooler may be more important than the weight of the oil. Dont forget your power steering fluid too, that gets the hotest of any of my fluids when I go wheeling. Reason, slow air movement and a lot of heavy use, aka extreme driving conditions.

 

Ford agrees with you. But the new 5w-20 oils are thnner by nature because they are designed for maximum fuel mileage. They make the OEMs look good on the EPA cycle and help meet CAFE requirements, so the OEMs recommend them.

5w-20's are a performance compromise, with greater weight being placed on fuel economy rather than protection.

Personally, I'll give up a little mpgs for a few more centistokes in the oil pan.

Everyone may feel free to disagree with me.