Oil Type

[udidwht]

Most vehicle manufacturers recommend an annual change regardless of miles. They don't know what it may have been exposed to while sitting around, plus lack of use makes contamination from water condensation likely (engine heat drives moisture away).

The only way to know with absolute certainty is via an oil analysis.  Run the oil a given number of miles and send in a sample. Once you find the sweet spot (OCI) stick with it. Most name brand oils these days will easily go 5,000+ miles or more than 1 year between changes. Condensation is not from sitting alone but the actual combustion process. If one only drives short amount of miles each start up than more condensation will accumulate overtime. Get the oil up to temp to rid condensation.

My oil preference...

Valvoline VR-1 racing 10w-30 with a Mobil 1 Extended Performance filter

 

[kenb1023]

My 2 cents...  Our 2008 Ford V10 powered A Class has had nothing but full synthetic since I got it with 18K miles on it.  I started out using Pennzoil but made a switch to Mobile 1 5W-20 when I got a great buy and it seems to run smoother.  I change it every other year since I am lucky to put 2K miles on it a year.  Any way, all my gas and diesel engines run full Synthetics.  My 99 Dodge Ram gets 5W40 Shell Rotell every 8K miles and has 175K and the only oil I loose on it is what drips from the vent tube.  Normal for a Cummings.  Our 08 Dodge Durango runs Mobil 1 and has 191K miles.  It gets change between 7 and 10K miles.  So I am a total Synthetic addict. 

 

[Gary RV_Wizard]

I'm not a synthetic addict, but I use them selectively based on my perception of the working environment.  My diesel coach got natural oil in the crank case cause I planned to change it (and filter) annually even though mileage was typically only 6000 miles or less.  Genset engine got whatever the big diesel got.  The Allison tranny got synthetic cause I didn't expect to change it until the fluid analysis said so (which turned out to be 12 years). Tranny filters got changed every 3 years, though.  My car engines get synthetic or synthetic blend because I work them harder and they run mostly in a hot humid environment as well. 

I've found one article that seems [to me] to be well-balanced on the synthetic vs "dino" oil question, not hyping either over the other.  It's short and not super-technical, so maybe it will help others make their own decision:
http://www.enginebasics.com/Engine%20Basics%20Root%20Folder/Oil_Synthetic_VS_Regular.html

 

[Ernie n Tara]

I'm exactly in line with Gary with the exception that I run full synthetic in the generator. The reason being that it gets more than the recommended hours if I change it annually when the coach diesel is changed.

Ernie