When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
[updated:LAST EDITED ON 16-Mar-02 AT 10:17 AM (EST)]Either oil will work just fine. The 80W90 means at 0 degrees the oil will have a vescosity of 80 and at 200 degrees the oil will have a vescisity of 90. A lower viscosity flows thinner the higher viscosity means it actually thinkens when it gets hotter due to additives they add in oil. When you buy a oil with the W in the middle the W actually means winter the # before the W is the viscosity in winter temperatures and the # after the W means the viscosity at summer temperatures which the API uses 200 degrees for an average temp when testing viscosity. But as for the W in a grade of oil all the W means is winter call the API if you don't believe me.
So the 80W140 means if you run in a hotter climate or pull a trailer alot the 80W140 would be a better oil since the viscosity raises to 140 at 200 degrees
Now for your question of limited slip or locker The rear might be a limited slip it depends what the customer who bought the truck originally optioned for as for the front it is a open differential
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.