6.5 TD Highway Mileage Poll by GMC Hauler

[redsuburban]

1 - Suburban
2 - 1500
3 - 4X4
4 - 2
5 - 3
6 - 16oz PS Gray
7 - 42 gal
8 - 4.10
9 - LT245 75R16
10 - Highway
11 - NO
12 - Elec
13 - Fact
14 - Auto
15 - 180
16 - Fact
17 - NO
18 - NO
19 - NO
20 - K&N
21 - EGR
22 - Fact
23 - Stock
24 - Stock
25 - Stock
26 - YES 15-50 Mobil 1
27 - 17 mpg
28 - It's always summer here
29 - 265,000

[HANK1948]

1.CREW CAB LONG BED
2.3500
3.4x4
4.2 no more than 70 on hway
5.2
6.no
7.35 factory add on 30 gals in bed
8.4.10
9.235/85
10.mud/snow
11.no
12.mech
13.20 max
14.auto
15.195
16.factory (changing soon)
17.n
18.yes
19.n
20.K&N off turbo
21.non
22.GM5
23.3.5 downpipe 4.5 straight no muffler
24.not sure
25.stock
26.n
27.14
28.summer
29.165,000

[_Scott]

1. Model: Suburban
2. Level 1500
3. 4x4
4. Driving Habits: 3
5. Tune of vehicle; 2
6. Fuel additive added every fillup in OZ: none
7. Size of fuel tank (Suburban is 42 gal)
8. Rear Gear Size: 3.55.
9. Tire Size: 245/75 R16
10. Tread style: Highway
11. Gear vendor: none.
12. Boost control: stock
13. Boost pressure setting (4-20lbs): stock
14. Manual/Automatic Trans: Automatic
15. Thermostat (160, 180, 190, 195, 205, 215, none): stock
16. PCM programming (Heath 1.0, 2.0, Kennedy 72/76/max, Westers): none
17. Timing Gear Y/N: stock
18. Intercoooled Y/N: stock
19. Mist injection Y/N: stock
20. Air filter (stock, stock w/ airbox mods, stock airbox with special filter, both, 97 and newer box, cone filter): stock
21. EGR/Non EGR: stock
22. GM Turbo Style (GM5,6,8, other): stock
23. Exhaust: stock
24. TDC offset set to (stock, or the value you have it set to): stock
25. Stock injectors/High pop: stock
26. Synthetic oil Y/N: No -- DELO
27. Highway mileage (not towing, best averaged over 3 tanks): 19.5
28. When mileage data was obtained: Summer
29. Approx miles on vehicle: 60000 (only used on weekends/trips)

_Scott

[DaveNY]

1 Suburban
2 2500
3 4x4
4 2
5 2
6 Stanadyne blue + 1QT clean engine oil
7 42
8 4:10
9 265x75x16
10 Hwy
11 -
12 Mech. TM
13 9
14 Auto
15 195'
16 stock
17 no
18 no
19 no
20 stock
21 non- EGR
22 stock
23 stock
24 -1.94
25 stock orig.
26 no
27 17
28 Spring
29 117,000

[HH]

1. Truck Extended Cab Long Bed
2. 3500 dual rear wheels
3. 4x4
4. Driving Habits; 1
5. Tune of vehicle; 3
6. Amsoil Cetane boost (5 - 6 oz)or fuel modifier (16 oz) every other or every three tanks
7. Size of fuel tank (Suburban is 42 gal): 30 - 32 ?
8. Rear Gear Size (3.23, 3.55, 4.10, ect): 4.10
9. Tire Size (ex; 245/75 R16): 235/85/R16
10. Tread style; Offroad, Mud/Snow, Highway: All terrian Radials
11. Gear vendor? (if so, od/ud ratio and how you use it):NONE
12. Boost control: Mechanical
13. Boost pressure setting (4-20lbs): 12 - 14 max
14. Manual/Automatic Trans: 5 speed manual
15. Thermostat (160, 180, 190, 195, 205, 215, none): 180
16. PCM programming (Heath 1.0, 2.0, Kennedy 72/76/max, Westers):NONE
17. Timing Gear Y/N:N
18. Intercoooled Y/N:N
19. Mist injection Y/N:N
20. Air filter: stock 97 and newer box
21. EGR/Non EGR: NON
22. GM Turbo Style (GM5,6,8, other): GM3
23. Exhaust : 3.5" to 4" w/ Donaldson Muffler, no cat
24. TDC offset set to (stock, or the value you have it set to):-
25. Stock injectors/High pop: Marine
26. Synthetic oil Y/N: Y - Amsoil 15-40
27. Highway mileage (not towing, best averaged over 3 tanks): avg. 19.5
28. When mileage data was obtained (Winter, Summer): Summer
29. Approx miles on vehicle:252k on truck, 10k on engine

[jmp1945]

1. 1999 Suburban
2. 2500
3. 4x4
4. 1
5. 3
6. 12
7. 42
8. 3.79
9. 235/85R16
10. M/S
11. no
12. stock
13. stock
14. Automatic
15. 195 (180 is stock)
16. BD
17. no
18. no
19. no
20. stock airbox, Amsoil filter
21. Non EGR:
22. stock (GM8?)
23. 4", no kitty
24. stock
25. stock
26. Delo 400 (quasi-synthetic)
27. 18.7
28. summer
29. 138000

[rustyk]

Everybody's got something so, so, NORMAL...


1. '94 Barth ["What the HELL is that?"] 28' Breakaway Class A motorhome
2. 8500? (I dunno, it has a GVW of 18K lbs.)
3. 4x6
4. 1 (As if there's anything else as an option)
5. 1
6. Injector cleaner and/or ATF only
7. 40
8. Dana 80 4.53 (I think - Mag-Hytec cover installed)
9. 8x19.5
10. Mixed
11. Gear vendor? Nope - no room and unnecessary
12. Boost control: Purely Stock
13. Same as 12.
14. Automatic Trans 4L80E (Mag-HyTec pan installed)
15. Thermostat: 2x195F (Kennedy Diesel kit installed)
16. N/A - DB-2
17. Timing Gear: N
18. Intercooled: N
19. Mist injection: N/A
N20. Air filter: Stock Wix, but this diesel pusher has far less restrictions - "Snorkle" is 4"
21. Non-EGR
22. GM Turbo Style: 5
23. Exhaust: 4" Turbo to ground
24. TDC offset set to : Stock
25. Stock injectors
26. Synthetic oil: N Total waste of money (I'm a former fuels and lube engineer)
27. Highway mileage: 9.8 mpg
28. When mileage data was obtained: Summer
29. Approx miles on vehicle: 52,500

[Slim shady]

1. Long bed extended cab
2. 2500, Single
3. 4x4
4. 3
5. 1
6. Bio diesel pump gas,
7. 36
8. 4.10
9. 235 85 R16
10. Mud/Snow,
11. N/A
12. Custom Electrical:
13. 15 psi
14. Manual
15. 195 winter, 180 summer, large diameter dual setup, 130 GPM pump
16. N/A
17. N:
18. Y: custom made
19. N
20. Stock mod, KN filter
21.Non EGR:
22. GM-8
23. 4

[GMC Hauler]

Updated.

We'll see how I move up... Installed new injectors and KD glow plugs a few weeks ago.

d.h., could you provided the missing information?

[gherrell]

BE CAREFUL!!!

I think that ECM programmer is quoting "Canadian MPG", which uses a different sized gallon that we us in the US (4.456L CA gallone versus the 3.785L "US gallon"). APPLES TO ORANGES comparison with his results. His results should read "20.4 to 21.1 US MPG" to be apples to apples, which is still great fuel economy but much more realistic than 25MPG!!!!

Please also note that he quotes the odometer reading in "kms", which is an additional clue...

[GMC Hauler]

BE CAREFUL!!!

I think that ECM programmer is quoting "Canadian MPG", which uses a different sized gallon that we us in the US (4.456L CA gallone versus the 3.785L "US gallon"). APPLES TO ORANGES comparison with his results. His results should read "20.4 to 21.1 US MPG" to be apples to apples, which is still great fuel economy but much more realistic than 25MPG!!!!

Please also note that he quotes the odometer reading in "kms", which is an additional clue...

Good catch...

Gove me a few days to make some adjustments..

Those of you who post in KM, please make it obvious to me so i don't miss it.

[ECMProgrammer]

BE CAREFUL!!!

I think that ECM programmer is quoting "Canadian MPG", which uses a different sized gallon that we us in the US (4.456L CA gallone versus the 3.785L "US gallon"). APPLES TO ORANGES comparison with his results. His results should read "20.4 to 21.1 US MPG" to be apples to apples, which is still great fuel economy but much more realistic than 25MPG!!!!

Please also note that he quotes the odometer reading in "kms", which is an additional clue...

Actually it's 1.201 of the US Gallon. 20.8 US MPG.
kms to miles is 1.62 ratio
I could confuse you further with litres consumed per 100kms....

Lyndon
www.ecmprogrammer.com
Westers Garage.

[gherrell]

Actually it's 1.201 of the US Gallon. 20.8 US MPG.
kms to miles is 1.62 ratio
I could confuse you further with litres consumed per 100kms....

Lyndon
www.ecmprogrammer.com
Westers Garage.

Well, your original post specified a RANGE of 24 to 26 MPG (Imp). Which, if converted to US gallons, would be 19.98 to 21.64 MPG (US). And trust me, you would not confuse ME with L/100km's. If you really wanted to confuse people, then give your fuel economy in furlongs/firkin (*0.88888889)