What type of oil is recommended in the owners manual or the tag under the hood for a 00 Mustang GT 4.6L. 5w20 or 5w30
5w-20 on our 01 and 02 and I'm fairly certain the 00 would be the same. Mobil 1's recommendation, to substitute for Ford's recommendation, is Mobil 1 0w-20. Just a little added FYI...
99's call for 5w-30 as well. I use 5w-20 in my 00GT (Mobil 1). the engine blocks were changed in 01 and call for 5w-20 since the ports in the engine were smaller and 5w-30 is harder on the engine since it has to push a thicker oil through smaller ports. at least thats what i've learned/heard while working for Ford all the newer engines (01+) used in the Ford vehicles call for 5w-20
I would take anything you hear in the dealership with a grain of salt. I certainly wouldn't consider it as the best place to learn about your car I believe what you are thinking about is that 99-00 Mustangs used the Windsor block whereas 01 and up use the Romeo block. The Romeo block was also used prior to 99. When Ford designed the 4.6 and started putting it in cars way back in 91 they specified 5W-30 for it and continued to do so until 2001. The purpose of the modular motor is that parts are interchangeable. Don't you think a change in tolerances would affect this interchangablity? If you look at the TSB Ford issued in 2001 the ONLY thing mentioned is fuel economy, nothing else.
2000 is 5w30. Ford switched to 5w20 for fuel economy reasons. You could have a 2001+ and use 5w30 and it will not hurt it, but you might see a slight reduction in fuel economy.
