My understanding is that 05/20 is the spec by the Feds for fuel mileage for the 4.0 engine (1993). My new to me 4x4 ranger just turned 130,00o miles, should I switch to a Mobile One product, 0/30 or other or just stay with Dino 05/20. Our temps get down into the 20's here in the winters and summers are high 90's and low 100's at times. Any thoughts? Thanks!

James

 

Use the oil weight recommended.

If you know the service history and it has been serviced with dino up to 130k I would not switch it over to synthetic. Synthetic is better oil but if you swap over you may have dino varnish that is plugging up some leaky gaskets that will get washed away.

 

I am willing to take the risk as some of the ideas around synthetic seem to be based on mythology - My truck unfortunately is often started in the morning and then driven a few short miles and then shut down -I think synthetic would be better for such short service cycles vs dino due to better start up lubrication.

 

I'm with Tsquare. That isn't a myth. Dino, as you call it :), has one type of detergent. The synthetic has a different kind (and more efficient/aggressive). The synthetic WILL start cleaning away any sludge left over time and miles. The leaking gaskets are a good possibility, BUT, not a guarantee. That being said, proceed at your own risk.

 

Thanks, yes, I am aware that buildup can be removed (not a myth). Service history was very good and I am hopeful that low miles will assist in switching over -might just go the Amsoil route -thanks!

 

That's cool. Good luck! :)