2002 Mazda Tribute Heater kills mpg

2002 MAZDA TRIBUTE
200,100 MILES • V6 • 4WD • AUTOMATIC
Avatar
JENN1209
  • MEMBER
  • 4 POSTS
I live in Columbus, OH and in the winter my tribute burns a little more than twice the fuel when I have my heater on than when I have my heater off. I get approx 10.6 mpg w/ heater on and approx 21 mpg w/ heater off. What could be causing this?
Nov 14, 2014 at 8:37 PM
Advertisement
Avatar
MHPAUTOS
  • ✓ASE Certified Mechanic
  • 31,937 POSTS
  • ASE Certified Mechanic
How are you calculating the fuel consumption?
Nov 14, 2014 at 8:46 PM
Avatar
JENN1209
  • MEMBER
  • 4 POSTS
I travelled a total 77 miles that day and I have a 15gal fuel tank which was full. I had the heater on during my travels (it was 25 degrees f out). At the end of the day I had half a tank of gas left. So 77miles/7.5 gal =something like 10.26666 mpg . If the heater were off I get between 20-25 mpg even in cold weather.
Nov 16, 2014 at 8:17 AM
Avatar
MHPAUTOS
  • ✓ASE Certified Mechanic
  • 31,937 POSTS
  • ASE Certified Mechanic
Gauge may be out of calibration, the best way to test is fill tank re set trip meter, do say 50 miles re fill and see how much is used,do this twice, with heater on and off do this test first,
Nov 16, 2014 at 12:01 PM
Avatar
JENN1209
  • MEMBER
  • 4 POSTS
My gas gauge is reasonably accurate. This fluctuation in mpg only occurs when I run the heater. The vehicle burns extensively more fuel. I've tested this multiple times including an assumption that it had to do with my gas gauge, that assumption left me stranded on the side of the road. I understand it doesn't make sense to anyone that running a heater could cause a vehicle to burn double the fuel but it does. I preserve my gas mileage by leaving my heater off which, while effective, is very uncomfortable when it's below freezing.
Nov 17, 2014 at 7:32 AM
Avatar
MHPAUTOS
  • ✓ASE Certified Mechanic
  • 31,937 POSTS
  • ASE Certified Mechanic
I will pass this on to others as I can't offer an explanation or a possible remedy as I can't see any possible connection between the two
Nov 18, 2014 at 12:55 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.