What's up guys! Yesterday I bought some Mc 5w20 for my 4.2 at Walmart,and I saw a lot of Mc synblend 5w30 and bought for my 4.0 Explorer,wich one have a better add pack and low wear number?? And can I use this 5w30 in my 4.2?

 

They are the same oil except for the viscosity as far as I know. Yes, you can use 5w30 in a 4.2, but why?

 

Because of the High miles on my Truck(210),and also I found all online onwer's manual said to use 5w30 and my door jamb sticker said it was build in 9/98 but it is 99

 

The 5-20 was a move by Ford to maximize fuel mileage. I would use what the owners manual specifies, unless you have reliable info otherwise. I'm surprised your oil fill cap doesn't specify the weight for the vehicle. It may be aftermarket. The 4.2 if I remember correctly, is just a punched out 3.8? Not one of Ford's more modern motors.

 

Yes my oil cap doesn't say nothing just engine oil

 

I've been using 5w20 in my 4.2 for 180k miles and it still only uses a quart about every 5k.