View Single Post
Old 08-07-2017, 01:47 PM   #8 (permalink)
vskid3
Master EcoModder
 
vskid3's Avatar
 
Join Date: Jun 2008
Location: Utah
Posts: 974

Civic DX (sold) - '97 Honda Civic DX
90 day: 34.15 mpg (US)

GTO (sold) - '04 Pontiac GTO
90 day: 22.62 mpg (US)

Green Brick (sold) - '06 Ford Escape Hybrid
90 day: 31.93 mpg (US)
Thanks: 193
Thanked 311 Times in 220 Posts
Most cars have the speedometer show a slightly higher speed than actual, possibly to reduce the manufacturer's liability for speeding tickets. The odometer is usually much more accurate, though factors like different tires can change that. If you have your scangauge show speed, it'll probably be pretty close to what your GPS says. The car knows the actual speed and just has the speedometer show higher.

Does your GPS have any sort of trip odometer? If so, you can reset that and the car's trip odometer before going on a drive and compare the two at the end (preferably a long highway drive).
  Reply With Quote