So my father in law has a 2000 Ford Excursion v10 Triton engine(Gas FYI)

I love driving this truck when I can, and its a beauty.

However, I recently learned from my father in law that he put 15w40 in his engine. Only reason i found out is that I was going to change its oil with 5w20 when he told me he used 15w40 in the last change. "The guy" told him it would be ok since that is what he had at the time.

Is it me, or does that number scare me for some reason? Im still going to change the oil tonight, but I want to know should I be worried about some other stuff besides the oil since he put 15w40 in it? I shouldnt stick with it, should i?

Should I be worried about internal damage of any sort? I have not noticed anything different since he has had that oil in there for about two months.

 

A high mile motor in, I hope, hot weather? Probably ok.

The low tension rings aren't going to like the thicker oil, especially on cold starts. You get an oil burner on cold starts, eventually leading to an oil burner all the time as the rings are "abused" on every start up.

That's my theory, based on a little fact.

I'd go back to the recommended oil and stay there. We have a 100,000 mile Lexus and a 95,000 mile Exploder running 5w-20 in blazing hot So Cal--no oil use in either one of them.

 

We live in Vancouver Washington... Gets a little cold in the winter. Summers are hot.

Anyways, should I have to worry about any internal damage? Also, when i change the oil, should i notice a little performance improvement?

 

If you had damage, you'd have a noise or a blue cloud or both by now.

You might pick up a tiny bit of mpg with the thinner oil, "performance" wise, I don't think it's going to shave a tenth off the quarter mile time....

 

Why on earth would you put 5w-20 in any of those engines, 0w-30 yeah, I sure hope you keep a REALLY good eye on your oil pressure.

I could see a ever sooo slight possible increase in MPG but WAYYYY shorter engine life.

 

Ford recommends 5w-20.

https://www.ford-trucks.com/forums/7...ar-v-10-a.html

 

5W-20 is what ford calls(take a look in the owners manual) for in the 6.8 and 5.4's. thats all i run, from -30F to 80+F it works great w/no issues.

 

I don't work on much "new" stuff, so if it's what they recomend factory in later years then yeah. In which case I'd personally see if I could search out a 0w20, But I would never put a 20 in a motor that when new wanted a 30, and I'll always go for the lowest W(first) number I can get my greasy hands on.

 

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Ford spends millions developing the engine, including the proper oil for it. Backyard mechanics, with ZERO testing, and just about that amount of knowledge, come up with a better solution for what oil to run. I just don't understand. I never will.

 

When I seetviced police fleets even in blazing hot summer weather at 90+ degrees outside with idle times of 8 hours+. I know is not a v10 or a 5.4 it's a 4.6. A 5.4 is pretty much a bigger 4.6, a v10 is just a 5.4 with 2 cylenders added at the rear. So that being said that ford modular motors will turn 300,000 miles usually on that " water" oil. I think ford spent enough on developing the motor With strict tolerances in mind. Also the cam followers are oil pressure driven. If you read the back of the jug of 15 40 it says " not for use in gasoline engines equipped with a catalyst" so pretty much every gas motor. 5-20 and 5-30 has been proven that there is no lesser protection with 5-20.

 

Exactly what I was thinking. I have never heard so many myths and assumptions until I got into the mechanic field. ............seriously

 

Exactly - I have a guy who comes into the shop every summer on his vacation and tries to insist I put Rotella 15w40 into his 2008 Pontiac G6!! Give me a break - I refused and turns out he uses it because he gets it for free since he handles fleet service for his company. He's just asking for trouble when the car needs 5w30. There are some older and higher mileage vehicles I switch to 5w30 vs. 5w20 after talking to the owners to reduce some consumption but certainly not recommended unless you have an issue.

 

We had most of our 5.4 and 6.8 trucks in our fleet rattling like heck on startup when I first started working at the phone company. I asked the senior tech what oil he ordered for our bulk tank, and he said "10w40, heavier the better for these junk motors!". We switched to 5w-30 and all of a sudden the rattling just about ceased. I, myself, run motorcraft 5w-20 semi-synthetic, I get it at autozone for as cheap as conventional oil. My v10 loves it. The 6.0 chevy ls motors clack and rattle if you put heavy oil in them also, I "fixed" a buddys chevy truck draining out the rotella 15-40 and putting in 5w-30. His truck was really sluggish from the computer backing the timing out cause it was hearing detonation, which was actually rattling from the too thick oil in the lifters.