---- Tom Hargrave <thargrav@HIWAAY.NET> wrote:

> Want to increase your mileage?

> Run synthetic 5W-20 oil

Really bad idea with a waterboxer.  Generally, it needs much heavier oil than recommended here, whether synthetic or not.  Follow the recommendations in the owner's book, or 15W50 or 20W50 if you don't have an owner's book available, unless you drive where it never gets hot.  Then you can run 10W40 (the temperature range given in the owner's book for this is from about -10 to 60 F, so a good winter oil in most of the U.S.).  If it gets brutally cold regularly where you drive, then the 5W20 is ok, according to my owner's book -- only in temperature ranges below 20 F, and then one should watch the ambient temperature and avoid prolonged or high speed driving if the temperature rises.  Our vehicles are quite sensitive to oil thinning at higher temperatures under sustained driving.

Now, to forestall the inevitable replies, yes, I do know that oil technology has changed since my owner's book was printed in 1990 or so (I have a '91 VW Vanagon GL Campmobile 2.1 waterboxer).  But viscosity and temperature have not changed.  The oil label reflects the viscosities expected (the numbers are not actual viscosity measurements, but rather an index that the manufacturers and regulators have agreed on) under specific conditions.  They take into account the changes in technology.

> Buy gas from a station that sells alcohol free gas - this will have the
> greatest impact

Excellent advice, for a number of reasons, but it does have a significant impact on mileage, simply because a unit volume of alcohol has less energy than the same volume of gasoline.

mcneely