[Shotimes] High Mileage Oil Findings

[Ron Porter]

An immediate  caveat......these are not scientific findings done under
rigorous test conditions, they are my casual findings, but they are good
enough for my purposes!

FWIW, I have a '95 MTX with 91K miles. The maintenance history before 68K
miles is unknown, and would probably be scary if I found out what it was.
Anyway, even after changing the trashed bearings at 86K, the minor oil leaks
are from both the front and rear seals, as far as I can tell. It is a minor
drip every time I park it, and standard oils required that a quart be added
every 1,200 miles. I started using various brands of high-mileage oil, and
here's what I have found so far.

Max Life (over 75K miles) oils used: Pennzoil, Castrol, Valvoline.

Rankings:

Castrol: Best I've found. It totally stopped oil leaks for the first
1,800-2,000 miles, then started with a reduced drip. I was not even a quart
low at 3k miles.

Valvoline: Worked quite well, leaking greatly diminished, and I recall
having to add a quart somewhere in the 2,000-2,500 mile range.

Pennzoil: Worthless as a high-mileage oil, it never stopped any leaks, I can
smell oil after the car get hot (usually this is the front seal dumping on
the y-pipe, I think). At the present rate, it will need a quart around the
2K mile mark.......BUT.....I put in 6 quarts, so it was a 1/2 quart high to
start with.

I will stay with Castrol, but would buy Valvoline if it was on a super sale.
I won't use Pennzoil again.

Ron Porter