When to change fluids, when I do alot of highway driving.

eccentriceccentric Member Posts: 1
edited April 2014 in GMC
I need some information regarding when to change fluids (oil,tranny,) as well as plugs and other maintinence. I frequently travel everday 125 km up in Canada, on country roads, with no traffic. I rarely stop on the trip, about twice and these are for stop signs. My speed is usually 90 km/h and I use cruise control most of the way. I park it in a heated garage and it is never out in the cold overnight.
The dealer tells me that the long distance service does not apply here in Canada because of the weather which is usually cold and the gas which is dirty. I think he is full of B.S. but I am not sure.
The manual says there is a long distance service schedule. Should I follow it?
I drive a 1996, GMC Jimmy with 166000 km (100000miles).


  • armtdmarmtdm Member Posts: 2,057
    Your type of driving is ideal and without the cold starts and short trips you are fine. Plus, you already have 60,000 miles on the vehicle and it is fine!
  • q45manq45man Member Posts: 416
    The standard test for oil is that it not double in thickness viscousity in 65 running hours this would only be 3,575 miles but you are running half the rpms [at 55mph] under which the test are conducted....the real question is how much blowby from rings your engine has and when does the oil filter fill up and no longer filter the oil. Most oil filters are not to spec [10 micron particle test] after around 3,000-4,000 miles but they are still filtering most sizes until around 5,000 miles.
    If it's very cold outside the oil temperature maynot stay above 212F to boil away the condensation [water vapor] in oil promoting sludge formation.
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