Why change oil once a year? - Page 2 - PeachParts Mercedes-Benz Forum

leathermang · #16 11-21-2009, 03:53 PM

I do not know how far you would need to drive it to do that..
but I do know that not driving it will sure make a mess in the engine.
We had a 318 Dodge farm truck which got started a million times to go maybe a hundred yards... then sat for us to load up stuff... then moved just a little ways..
but the oil was changed religiously at 3000 miles...
When I opened up the valve cover once I was shocked... never had any of my engines looked like that... it was covered with thick light brown slim all over the valve mechanism... We always used Mobile oil at that time and changed the filter each oil change.... my other engines looked clean as a whistle inside.... the main difference was the short trip nature of its existence....

Skippy · #17 11-21-2009, 09:20 PM

Interesting thread. Where I work, we use the Navy 3M system for maintenance scheduling. Most of our vehicles call for an oil change every six months. A few are supposed to have it changed every 3 months. Most of our equipment doesn't get driven very much. Extreme example: 1994 model truck with 2700 miles on it. More typical example: 5-10 year old Hummvee with under 5000 on it. Everybody is certain we change oil too much, but nobody has a good scientific answer on how often we should actually be doing it, other than resorting to oil sampling, which would probably be a good idea.

On my own cars, I have run into being over a year on oil with less than 3000 miles two times. The first time, I changed it at the one year mark. On the other (the gasser), I can tell the oil still looks new, so I'm holding off for a while.

soothappens · #18 11-22-2009, 12:11 PM

Condensation and acids in the oil are the main reason for changing the oil. Not sure on the new synthetics . Oil sample cost is 10.00 plus fuel to drop off and pick up . Just changing the oil , not the filter would seem to cost the same labor and dollar wise if you do it yourself . Then change the filter once a year. Only on low use vehicles, not short trip ones. Meaning the vehicle gets up to operating temps and is driven afterwards , but maybe once or twice a month.

leathermang · #19 11-22-2009, 12:21 PM

Quote:

Originally Posted by soothappens

Condensation and acids in the oil are the main reason for changing the oil.

That agrees with what I have been reading for about 40 years.

soothappens · #20 11-22-2009, 12:57 PM

Quote:

Originally Posted by leathermang

That agrees with what I have been reading for about 40 years.

That agrees with every fleet mngr. in central and south Tx.( extreme conditions) that I've been working for the past 20.

pawoSD · #21 11-22-2009, 04:59 PM

I guess I don't have any cars that meet that criteria....my sibling's cars are both only driven about 5-10 miles max at a time......and they drive only about 3,500 a year at most....so I do them once a year. My cars both get at least 2 a year because they meet the 4,000 interval more than once.....same for my dad's cars....