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2006 GMC Sierra 2500 HD 6.6L Poor Fuel Economy
Posted to GM Driveability on 10/14/2008 5 Replies

I have a 2006 GMC K2500 6.6L Diesel with the Allison automatic trans. This started out getting 18 mpg. and 14 mpg. towing a fifth wheel camper. Now my mileage has dropped to 10.5 mpg. towing. This is on long trips of several hundred miles at a time. I have che...

5 Replies Received (View Replies)

 
Message Closed w/Summary

car Vehicle Data

2006 GMC Sierra 2500 HD

VIN [No VIN Available]
Engine6.6 L / 8 cyl / DIESEL
Trans6-speed Automatic (Electronic)
DeliveryFI
EmissionsOBD-II Compliant
SymptomsPoor Fuel Economy
OccursAlways
Message Closed w/Summary

car Vehicle Data

2006 GMC Sierra 2500 HD

VIN [No VIN Available]
Engine6.6 L / 8 cyl / DIESEL
Trans6-speed Automatic (Electronic)
DeliveryFI
EmissionsOBD-II Compliant
SymptomsPoor Fuel Economy
OccursAlways