M1 FS 5w20 '99 Mustang GT 900 mi

Joined
Oct 29, 2014
Messages
1
Location
STL MO
Hello all, First time poster here. Wanted to post up the UOA I just got on my '99 GT. I just got this car and wanted to do a quick oci on it because I wanted to see what the UOA would say. This car has had about 30k track miles on it and the previous owner was very, very good about changing fluids. He changed the oil pretty much every track day, maybe two. I followed his lead and changed it after my first TD with it. The other ~800ish miles was just me driving around town. The previous owner ran 5w30 in it but I ran 5w20 on this because I thought that's what the car specified, however, I can attest to the back-spec beginning in '01. Being a '99, my car has a 5w30 sticker on the hood. I was shocked. I didn't even check, I just assumed that all 4.6s took 5w20. For the use this car sees though I am going to just stick with 5w30. Still though, the 5w20 was holding up great and BSL said I could probably have done another TD with it! Perhaps this will help calm some debates over 5w20 for "hard use". Let me know what you all think.
 
Joined
Nov 11, 2010
Messages
9,783
Location
Saskatoon canada
Ford back spec'd that engine for a 20 grade. I had the same car. Ran at least 500+ pounds of nitrous through it without any engine problems. I ditched the 2v because of it spitting out plugs. I put a 4v in it from an 04 mach 1. Then that car became real fun. Anyways I ran everything from 20 grades to 40 grades in mine and I can truly say the car had more pep using a 20 grade. If your going to run intervals less than 5000 miles use a good conventional. Spend the savings on fuel. In 2001 ford transitioned most engines to a 20 grade and back spec'd most everything else other than the early 90s cam in block engines.
 
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