This data is about a year old, but I thought I’d share it with the group of fanatics that we are. The vehicle is a 1996 Grand Cherokee 4x4 with a 242 ,4.0 L, inline six-cylinder. At the time of the sample acquisition the vehicle had 101,311 miles on it. The oil had that was analyzed had 24,033 miles on it and was in the Jeep for 11 months and 16 days. The oil was installed on 12/9/2000. The oil filter was changed on 6/1/01 at 10,655 miles. The oil was drained and a sample was taken on 11/24/2001. The only oil added during the test period was during the six month filter change. Added back ½ quart. The oil level never dropped below the full mark on the dipstick during the test period. Here are the specifics:
Oil type: Amsoil 10W-30 ATM, 6 quarts.
Oil filters Amsoil SDF 15, initial filter and six month change filter.
Air Filter: K&N Filtercharger P/N 332248. Installed new on 12/9/2000. Not serviced during test period.
Analysis performed by Oil Analyzers Inc.
Physical Properties:
Glycol: Neg
% Water: % Fuel: 1.2
Viscosity 40 C: NA
Viscosity 100 C: 13.3
% Solids: TR
Oil Degradation:
Soot: NA
% OXD: 33.3
% NOX: 74.3
TBN: 8.2
TAN: NA
Spectrographic Analysis, PPM
Fe: 48
Cr: 2
Pb: 23
Cu: 10
Sn: 3
Al: 10
Ni: 2
Ag: 0
Mn: 1
Si: 17
B: 24
Na: 13
Mg: 322
Ca: 3163
Ba: 0
P: 1222
An: 1522
Mo: 7
Ti: 0
V: 0
Cd: 0
Results of test performed indicate:
Nitration elevated
Viscosity is out of indicated grade
Oil at service limit based on miles/months
Change oil and filters, if not done when sampled
resample at next regular interval
Note: About 1/3 of the way into this test, my Jeep developed an exhaust manifold leak. The exhaust manifold was not replaced until after the test. This likely accounted for the elevated nitration since leaking exhaust manifolds result in a rich fuel mixture in SMPI vehicles. Unfortunately, I was not able to conduct a follow-up analyses with the subsequent oil change. Wife had baby, got busy.
[ December 12, 2002, 04:46 PM: Message edited by: darrenc ]