Hello, I just bought a 2003 with 2.3 engine 41000 original miles. Fella I got it from is an old school guy and said there is no way he would put 20 wgt oil in an engine, he always used Valvoline 10w30. Heres my question, what happens if I change back and use Mobil 1 5w20? The truck runs perfect and has plenty of power for a 4 banger so it aint been hurt. Just worried about changing back to 5w20. Help!

 

I was in the same boat when I bought my truck, the guy that had it before me put 10w30 in it to. I was hesitant at first to, but I went ahead and put 5w20 in it since it calls for it, and I run it hard. So far I havent had problems with it. The only thing I will say is, I tried mobil 1, and my truck began to leak oil from the rear main seal. I took it out, and went with castrol gtx conventional oil, and it hasnt leaked since.

 

My truck runs perfect on Mobil 1 5w-20, I'll continue using it until it screws something up.

 

Oh mine ran fine, it just pissed me off that it leaked. Im not saying it will cause everyones to, but mine did and I just took it out because of that.

 

You need to blend in from a conventional oil to synthetic if you go straight over you will leak no matter what brand you use. 2 changes with a blend then synthetic and your golden

 

Good idea! Thats what I'll do............

 

I never leaked anything when I switched. I've never heard that before...

 

ok i'll play devil's advocate. why mess with a good thing? if it runs well on dino 10w30 then why switch? i use the oil ford recommended back in '97 in my engine, dino 5w30. it can easily go 5000 miles between changes, and starts great in the winter.

 

Thats what I thought too,but Ive been hearing all the claims about better mileage with synth so i want to give it a shot. 3.95 a gallon here in Indy today.

 

use 20w 50 in my 93 explorer
if not it burns it to quck i use it in the winter with know problems

 

is RI suddenly in the tropics...?? lol

 

Yeah, well ive used motorcraft synblend 5w20, and thats never leaked on me either.