# Show 1206: Sonoma Fuel Gauge

**URL:** <https://community.cartalk.com/t/show-1206-sonoma-fuel-gauge/70927>\
**Category:** Maintenance/Repairs\
**Tags:** gauges, gasoline\
**Created:** [February 13, 2012, 11:44pm UTC](https://community.cartalk.com/t/show-1206-sonoma-fuel-gauge/70927 "2012-02-13T23:44:10Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![DavidKelly](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@DavidKelly](https://community.cartalk.com/u/DavidKelly)\
**Post date:** [February 13, 2012, 11:44pm UTC](https://community.cartalk.com/t/show-1206-sonoma-fuel-gauge/70927/1 "2012-02-13T23:44:10Z")

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Would be simple enough for a rough calibration of the accuracy of the caller’s fuel gauge. Too simple to be a puzzler. At indicated 3/4 tank fill and log the result in miles and gallons. Do it again at 1/2 tank. And again at 1/4 tank. I think one will find the tank is at about 1/3rd full when 1/2 is indicated.

I think MPG will be essentially the same for each fill but there will be more variation for filling at 3/4 because if repeatability in just what is a full tank is ± 1/2 gallon then there will be more error in 4 gallons ± 1/2 than for 12 gallons at 1/4.