Hi, I plan on changing the oil in my 4.6L V8 2000 Mustang GT today, but I'm having a bit of a problem. The oil cap says to use 5w-20, but the owners manual says to use 5w-30. Which should I use?
Also, what brand of oil filter do you recommend? I bought a fram filter but just read that they're pretty much garbage and I don't want garbage in my car.
Thank you in advance,
C.O

 

I also read Fram is terrible. I use motorcraft oil filters, as they work well and are Ford spec parts.

As far as the weights, I can't tell you which one to choose because I don't really know which one is better for you. If the manual says 30 and the cap says 20, you can rest assured that either 20 or 30 will be fine.

 

The first number is much more important than the second. 5w 20 or 30 is fine, you can even run 10w 30... but I don't, and don't think its a good idea. Fram filters are great filters, pretty much all big brand filters are great filters... so forget all the TV BS. Different oils do come from different sources, that said in reality... oil is oil. There will be zero difference for you between running mobil clean 5000 and auto zone el cheapo recycled oil. This is super duper true for running synthetic oil... you can buy the cheapest syn and it will make zero difference (as opposed to something like royal purple) In any stock motor if you run royal purple or redline your just wasting your money. Now if you have a built race motor with crazy tolerances or special mods then oil matters ALOT.

 

I agree with most of what you said Fobra. I disagree with the recycled oil comment. So long as the SAE and API matches or is better than recommended it's 'ok' to use recycled oil. Recycled oil is not as tightly regulated as new use oil and therefore may not go through the same ratings process or testing as new oil.

The API ratings are there for detergency factors. If you use an oil that is not rated to meet the API requiremnt of your engine and you have ANY internal motor problems during warranty, you could void the warranty when the OEM asks for the records.

 

That's weird about the oil weight difference.I'd go by the oil cap, or see what's on the computer at Autozone.

As for the oil itself I'd use the Mobil 1 synthetic.It may cost a little more,but not really once you figure in a cooler running motor 1-2 more MPG, and twice the mileage between changes.

The Motorcraft filters are fine.

 

Sometime around that year model the oil weight recommendation changed. You've probably got a copy of the manual that shows the older recommended weight. In subsequent years, the manual was revised to reflect a recommendation of 5w-20, and it became recommended for previous years of that motor as well. At least as far back as 1999, I'm not sure about pre-1999 4.6 engines. The lighter weight is what Ford currently recommends due to the tight tolerances on the 4.6 motor, and to enhance fuel economy.


Here's a link to the TSB that specified the change. Note it states 1996+ 4.6 GT's. I wasn't sure how far back this applied to, until I dug the TSB up.

For the filter, I'd go Ford Motorcraft. Avoid the cheap Fram filters.

 

imho the mobil 1 is hard to beat. i got a great story about it but it will take to long to type it. the motorcraft filter is fine as is a napa gold filter.
STAY AWAY FROM THE FRAM!!!!

 

I always try to use Motorcraft but if I can't get it I use Wix

 

As a sidenote on filters, unless things have changed recently, Purolator makes the Motorcraft filters. I think Ford provides a slightly different specification for their Motorcraft filter though. So the Purolator filter for our cars will be slightly different.

 

I use 5w-20. Fram is fine and so is motorcraft.