Overhead mileage computer verses Hand Cal

[BigGunZ]

I've found that the most accuracy is obtained by resetting it before starting the truck after a fill-up. I get nearly +/- 3/10 this way compared to hand calcs. Resetting it once moving throws it way off.

 

[RHildreth]

I posted this on another thread. The last two columns are of interest here. I reset my overhead at each fill-up. I can't tell when the overhead is high or when it will read low, but it is accurate enough to look for trends as was mentioned in another post. The first two tanks the mpg numbers are the calculated. I didn't note the overhead on them.



Here is my history from my logbook. I have this on an XCEL spreadsheet with comments about what I was doing that would effect mileage like pulling my travel trailer, 4X4 low range operating, cold weather, etc. I don't know how to attach a file though. As you can see, there are several 20 plus tanks. Not just short trips.



To date, I have purchased 1555. 586 gallons of diesel at a cost of $3,282. 20. Ave mpg for the life of the vehicle with all fuel purchased and all miles (minus whatever the dealer had in it when I drove it off) is 18. 06 mpg. I can't complain. The Bronco it replaced never got over 13 mpg and it sure couldn't pull a trailer like this beast.



Sorry about the columns not lining up, it looked good before I previewed.





Date Odometer Trip miles Gallons Overhead Calculated

1/30/2004 239. 6 239. 6 22. 299

2/10/2004 641. 9 402. 3 27. 291 14. 74

2/26/2004 1063. 9 422. 0 25. 772 16. 37

3/11/2004 1558. 9 495. 0 28. 874 17. 4 17. 14

3/23/2004 2092. 3 533. 4 28. 590 18. 1 18. 66

4/7/2004 2603. 9 511. 6 27. 990 18. 6 18. 28

4/21/2004 3076. 9 473. 0 27. 070 18. 3 17. 47

5/5/2004 3530. 3 453. 4 24. 708 17. 8 18. 35

5/24/2004 4088. 8 558. 5 29. 492 18. 1 18. 94

6/1/2004 4591. 4 502. 6 25. 450 19. 8 19. 75

6/16/04 5088. 6 497. 2 26. 936 18. 3 18. 46

7/1/2004 5630. 3 541. 7 29. 879 18. 0 18. 13

7/3/2004 6183. 0 552. 7 30. 326 17. 0 18. 23

7/5/2004 6638. 0 455. 0 22. 294 18. 8 20. 41

7/7/2004 7018. 0 380. 0 21. 175 17. 4 17. 95

7/7/2004 7293. 0 275. 0 15. 529 14. 9 17. 71

7/19/2004 7819. 6 526. 6 26. 568 18. 4 19. 82

7/30/2004 8203. 9 384. 3 20. 621 17. 8 18. 64

8/1/2004 8412. 0 208. 1 15. 513 17. 2 13. 41

8/17/2004 8910. 2 498. 2 25. 180 18. 8 19. 79

9/1/2004 9434. 2 524. 0 26. 950 18. 5 19. 44

9/14/2004 9991. 9 557. 7 26. 760 19. 4 20. 84

9/27/2004 10446. 9 455. 0 22. 890 18. 9 19. 88

10/8/2004 10863. 0 416. 1 23. 541 18. 4 17. 68

10/19/2004 11354. 3 491. 3 24. 280 19. 1 20. 23

11/1/2004 11825. 6 471. 3 25. 124 17. 8 18. 76

11/5/2004 12182. 1 356. 5 23. 701 15. 6 15. 04

11/10/2004 12559. 5 377. 4 30. 055 11. 6 12. 56

11/13/2004 12898. 5 339. 0 20. 963 16. 2 16. 17

11/15/2004 13445. 7 547. 2 25. 010 21. 6 21. 88

11/27/2004 13956. 4 510. 7 26. 863 18. 7 19. 01

12/10/2004 14344. 6 388. 2 23. 811 17. 0 16. 30

12/26/2004 14806. 5 461. 9 25. 015 16. 7 18. 46

1/4/2005 15022. 8 216. 3 15. 175 16. 2 14. 25

1/16/2005 15426. 3 403. 5 27. 336 15. 7 14. 76

1/31/2005 15898. 6 472. 3 26. 415 17. 0 17. 88

2/11/2005 16357. 2 458. 6 25. 736 17. 4 17. 82

2/18/2005 16759. 7 402. 5 20. 900 19. 6 19. 26

3/3/2005 17237. 3 477. 6 26. 725 17. 8 17. 87

3/18/2005 17731. 9 494. 6 27. 511 17. 3 17. 98

4/2/2005 18199. 6 467. 7 27. 135 17. 2 17. 24

4/8/2005 18514. 4 314. 8 17. 160 16. 4 18. 34

4/9/2005 18860. 8 346. 4 20. 078 16. 6 17. 25

4/9/2005 19271. 8 411. 0 22. 697 17. 6 18. 11

4/17/2005 19604. 9 333. 1 16. 421 18. 0 20. 29

4/28/2005 20068. 5 463. 6 25. 532 17. 5 18. 16

5/5/2005 20299. 4 230. 9 14. 079 17. 0 16. 40

5/18/2005 20795. 7 496. 3 27. 054 17. 6 18. 34

5/31/2005 21298. 0 502. 3 27. 296 17. 5 18. 40

6/13/2005 21782. 7 484. 7 25. 465 17. 6 19. 03

6/24/2005 22340. 9 558. 2 27. 205 19. 1 20. 52

7/14/2005 22870. 7 529. 8 27. 005 17. 9 19. 62

7/27/2005 23395. 4 524. 7 26. 066 18. 4 20. 13

8/12/2005 23898. 1 502. 7 26. 493 17. 7 18. 97

8/30/2005 24384. 1 486. 0 25. 194 17. 7 19. 29

9/9/2005 24766. 2 382. 1 19. 454 18. 3 19. 64

9/17/2005 25228. 3 462. 1 27. 596 16. 6 16. 75

10/5/2005 25750. 4 522. 1 25. 749 18. 1 20. 28

11/2/2005 26264. 9 514. 5 27. 562 18. 8 18. 67

11/14/2005 26599. 4 335. 0 17. 750 17. 7 18. 87

11/15/2005 26807. 5 207. 6 15. 460 15. 8 13. 43

11/19/2005 27028. 1 220. 6 19. 605 11. 2 11. 25

11/29/2005 27447. 7 419. 6 24. 307 17. 0 17. 26

12/9/2005 27934. 4 486. 7 26. 905 18. 8 18. 09

 

[Byershome]

Mine always reads about 2 mpg lower than what it calculates by hand. Long trips short trips it does not matter always right at or near 2 mpg. I'm getting 19-20 in the city and 21-22 hwy.

 

[JVolpe]

Update since my last post. I reset my overhead after every fillup before driving. It is very consistent. With my current performance stack for the last 8,000-9,000 miles it consistently reads 4. 1mpg higher than hand calculated. At least I have seen 23+ on the overhead on trips, just wish it was the actual and not the imaginary mpg.

 

[Coyote556]

i always reset at every fill up as well. my overhead is always 1. 5mpg (average) better than reality. I am still unhappy with the fuel mileage on this truck. :{

 

[GSatler]

the reason it resets is u have a bad connection or unplugged temp. sencer just to the right of your left headlight.



after i got the pinion factor right on, my overhead mpg. is right on + /- . 2 mpg

 

[SmithB]

What is a pinion factor?