[Healeys] Gas Mileage from Conclave

[Bob Spidell]

Hi Gary,


I've been doing a lot of "self-help" on my speedometer lately, so I've learned quite a bit about it.

The linkage between the cable and the odomoter and trip meter is hard gearing so it's not likely your odometer is off (if a gear was skipping you'd read low).    If you have lower profile tires than stock--who doesn't ;)--your odometer would read high (the difference between a 26" dia. tire and a 25" dia. tire would cause a 4% discrepancy, for instance).

Also, GPS indicates linear distance between pt. A and pt. B, and may not account for small turns between two points.  However, I believe the newer GPSes sample quite often so this may not be significant.


bs

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Bob Spidell         San Jose, CA        bspidell at comcast.net
'67 Austin-Healey 3000             '56 Austin-Healey 100M
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 -------------- Original message ----------------------
From: Editorgary at aol.com
> FWIW: Driving from Los Altos/San Jose to San Diego and back, I used 62 gals 
> of gas, costing about $290 to go a nominal 1053 miles, for an indicated 15.6 
> mpg.
> HOWEVER, that mileage included both crusing speeds and stop-and-go traffic on 
> highways and city streets. On the one stretch where we were able to cruise 
> continuously for 199 miles I managed a nominal 18.95 mpg. 
> I say "nominal" because when I checked my Garmin, I discovered that I had 
> actually driven only 990 miles, so my odometer reads 106 percent higher than my 
> actual mileage. So, adjusting for that I got an overal 16.7 mpg for the trip, 
> with 20.1 mpg on the one and only straight 65 mph cruising stretch.
> BTW, I have an early 3000 engine, but it was rebuilt with a BJ8 cam, if that 
> makes any difference, and based on plug examination, it runs a little rich.
> Cheers
> Gary