Oil for 2002 3.8L Mustang - 5W-20????

BobGPz

Registered User
I just spent an hour doing a new oil change on my Ex's 2002 Mustang. It has a 3.8L V-6. Very similar externaly to our 3.8's.

After putting the oil in (Mobil One 10W-30 Synthetic @ $6 per Quart), I put the stupid filler cap on and low and behold it says 5W-20.

20 Weight???? Do they even make such a thing? Could use some opinions/advice weather I should drain the new oil/filter and find some 5W-20.

Dealer closed on Sundays..so I can't call them and ask. I live in Washington State and the weather has been averaging 35'F - 65'F.:confused:
 
10W30 is a pretty thick oil to run in that new of an engine and in that cold of a climate. 5W20 is definitely offered at your local auto parts store. Personally, I prefer to use 5W30 in my 94 LX (which has a 2000 3.8L V6 in it, the same engine as the one in question), and I'm located in the Midwest.


-Rod
 
That's what I figured. She bought the oil, but then again I didn't question the viscosity either. I best drain it out. Maybe into a REAL clean pan and can put it into my SC. It's due for a change...I did NOT start her car so I would assume the filter does NOT need to come off...Thanks RaceCouger.....
 
Ford specifies 5W20 oil in most of their gasoline car and light truck engines since 2001 model year. This was done to get a 0.6% increase in corporate average fuel economy ratings.

Prior to that, 5W30 was the recommended oil ... which is thickest that I would suggest using in the Mustang, especially in a colder climate. The first part of the viscosity number, 5W, is a rating of how the oil will react and perform in cold temperatures. So using 10W oil just gives you less protection on cold startups, because the oil will not flow as freely to the top of the motor. On some OHC motors, that can be deadly.

cheers,
Ed Nicholson
SCCoO
 
Yeah.

And on top of it not flowing as well, manufacturers are running tighter and tighter bearing clearences for more noise reduction, quiter and smoother running motors. It's harder for that oil to flow in such tight spots. Which is what I beleive to be the major driving force in recommending the lower oil viscosity. Not necessarily for better gas milage.
 
OK, I went down and got the correct oil. Valvoline & Havoline is all they had in that viscosity. Needless to say after Michael Andretti blew so many engines I was not buying the Havoline.

I too was a little leary of 30W as I know the newer cars run tighter clearances. Can't really blame her for buying that weight as I would have bought the same stuff for it too. Never heard of 20W until I put that filler cap on. Good thing the 5W-20 was written on there. That 5W-20 was like water! Oh well.

Thanks again Rod, Ed, and 91Blown.:)
 
i live in The Idaho panhandle where the tempurature averages high 20's in the winter and 80's in august....and i run 10w30 in all my vehicles year-round....but then again everything i have has over 100,000 miles on it, plus they are older so the clearances are not as tight. I'd probably run a 5w30, rather than 5w20...you get the same cold weather flow, but also more warm weather protection so you can run it year-round. Oh, by the way (this one really blew me away) they now make 0w20 motor oil. yes that's right....0w20. i bet that stuff IS water....:)
 
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