Re: MPG and oil temp

[anderson@msai.mea.com (David Anderson)]

On Apr 21, 10:29am, Jeffrey J. Hoover wrote:
> Subject: MPG and oil temp
> Hey guys & gals-
>
> I'm enjoying having instant access to the data on my VR6, but I'm curious
> how it compares.
>
> Two questions:
>
>    1.   What kind of average MPG are you getting over a tank of gas? My GLX
> 	only has about 2,400 miles on it, so it's not really broken in yet.
> 	I feel pretty good if I get above 22, but I'm also having to get gas
> 	fairly often... Yeah, I know, it varies according to how aggressive
> 	you drive. :-)

For about the first year or so I had my car, the MPG indicator showed about
26mpg on average driving to and from work.  Much of that was highway driving.
 It also on occasion showed as high as 29 and 30mpg on longer interstate trips.
 It seemed to get the best gas mileage averaging around 80mph.

After about a year, the car developed (what I think was) an electrical glitch,
which caused the coolant temp gauge, oil temp gauge, and fuel gauge to give
really weird readings.  (Occasionally, the temp gauge would jump all the way up
to the right, like it was overheating, then plop back down to the middle, in a
matter of seconds!)  That's since quieted, but now my MPG gauge usually reads
about 21mph to and from work, and no higher than 26mpg on the interstate.
 Don't know if / how any of this is related...

>
>    2. 	I saw Abe (I think) mention that he doesn't push the engine
above
> 	3,000 RPM until after the oil temp gets above 180. Is this a good
> 	rule to follow on a regular basis? Do others have guidelines on this?

This is generally a good rule.  Keeping under 3000rpm may be a little bit
overkill, but it certainly doesn't hurt.  I don't push my engine hard at all
until the oil temp registers on the oil temp gauge (about 125 degrees F?).
Motor oil works its best at just above 200 degrees.  Not pushing the engine
hard before it's warmed up will certainly add to the life of the engine.

As an aside, I have a friend who had a ski boat identical to mine.  When I took
my boat out, I'd baby the engine, until the oil temp got up, and the oil
pressure went down to reasonable levels.  My friend would leave the dock at
full throttle as soon as he hit the water, never giving the engine time to warm
up.

Several years later, my engine runs like new!  His does too.  But only because
it IS new.  It's the fourth engine he's had in his boat.

(Extrapolate this story to your car!)

Dave
anderson@msai.mea.com