On Sat, 29 Aug 2015 13:08:27 -0700 (PDT), Uncle Monster
wrote:

On Saturday, August 29, 2015 at 1:57:04 PM UTC-5, Oren wrote:
On Sat, 29 Aug 2015 00:14:01 -0400, Ed Pawlowski wrote:

On Fri, 28 Aug 2015 10:07:49 -0700, Oren wrote:

On Fri, 28 Aug 2015 12:57:14 -0400, "Percival P. Cassidy"
wrote:

-old (140K miles) Chrysler and doing oil changes at about
4000 miles. The owner's manual doesn't mention synthetic lubricants but
specifies a time period after which oil should be changed -- "x miles
or x months, whichever comes first."

I've never understood the "x months" thing. If the car is not being
driven, except on Sunday, why change the oil until the "x mileage" is
reached?

If you take a lot of short trips the oil can get contaminated with
moisture as it is not heated up enough to get rid of it. Over time
things can start to gum up, I'm told, thus the 6 month recommendation.
My wife's car used to be changed once a year. She never hit the miles
mark.

Makes sense. In the Mojave desert summers, it doesn't take much to
bring the engine temperature up, but I see the point of longer runs.

I'd take my vehicles out on the interstate for exercise on a regular basis and blow them out. I'd make several full throttle runs to burn the carbon off the plugs until the engine ran more smoothly. Even a horse needs exercise. ^_^

[8~{} Uncle Car Monster
Referred to around here as a "polish tune-up"