352 miles on 29.6 gal.=11.9 mpg Help!!!!!!!!!!!!!!!!!!!!!!!!!!!

[DAWG-1]

Re: Check your correction factor

Originally posted by NVR FNSH

Not to make you feel any worse but using 9-11% for the tire correction is too high. I have 315/75R16 Americas Tire Pathfinder ATRs w/4. 10 and the odo is only 5-6% off when checked against my Garmin III+ GPS. I'm averaging 15. 8 mpg over ~29k miles - combined city & hwy. I typically drive 70-72 mph on the hwy.



Brian

I dont have any fancy gadgets. I used basic math. The difference between my original tires and my new tires and figured the difference. You should know exactly how far off you are if your gadget is right . I gave an approximate since our tires are not identical. Sam.

 

[NVR FNSH]

DAWG-1,

I used basic math for the correction factor as well & came up with 9%. When I got the GPS I figured out that 9% was too high for my truck/tires/air pressure. Just trying to help out.....



Brian

 

[TXRam]

I did the same as both of you for mine (different tire - starting and ending). The speedo didn't show as far off using the GPS, but I also used the Odo function on the GPS and it matched the calculation. So my Odometer and Speedometer have different errors.

 

[Skyjacked Ram]

Sounds like something is definately off.



Just got back from a round trip from Troutdale Oregon Flying J to Spokane Washington... 33in tires, 4. 10 rear, canopy with approx 1200lbs in the back and cruise set at 70mph. 709. 8miles round trip burned 40. 846 gallons... . 17. 358 mpg. Funny thing is 16. 89 going up and 18. 2 coming back. Go figure



Around town I get high 14's to mid 15's...

 

[KatDiesel]

I found a fuel ticket laying here.



390. 4 miles and it took 27. 68 gallons = 14. 1



This does not include any correction for my 285's vs 265's.



I drive it pretty hard, so I guess I can't complain.

 

[JMoglia]

Howdy guys,I also have 1 ton dually 981/2, 24V with utility box enclosed I weigh in at 10,200 GVW is 10,500,I have auto trans,duall 4'' stacks with just the stock resinator,K&N RE0880,355 rear end,I have not done any bombing yet,I drive hard combination surface roads and highways I get around 14 MPG AC on all the time I got rid of my psychotti box and made one out of sheetmetal,patched hole in firewall and am now working on new induction system from stock fender location aswell as from fog light holes,I'll try any sorce of air as long as it is of positive pressure,not like firewall with negative pressure,I am trying to get some pics on line of rig. good luck yall with your rigs, Joe Moglia