Engine/Transmission (1998.5 - 2002) Best mods for fuel economy?

[VIPERBLUELX]

My current mods are Edge Comp (tapped) and full 4" straight exhaust, and a BHAF. What other mods can I do to increase fuel economy? This truck is a daily driver and is 95% of the time unloaded. I'm sure the 35" tire diameter is hurting me some but they aren't going anywhere. Would some RV injectors increase or decrease fuel economy?



thanks



Mark

 

[hdtrukn]

Hey Mark

They are probably the best gain out there. I got 55HP and a 4mpg jump.

I think I may have had a bad injector from factory.

Add them to your Comp. and you will have fun.

Scott

 

[CToney]

FASS helped the milage and power in my brother's '01. I think his old pump was weak. He has 4" exhaust, BHAF, and an edge ez w/ 6sp and gets good mpg.

 

[Forrest Nearing]

the injectors should help



driving 5mph slower than usual helps a LOT

 

[mhenon]

Hey Mark

They are probably the best gain out there. I got 55HP and a 4mpg jump.

I think I may have had a bad injector from factory.

Add them to your Comp. and you will have fun.

Scott

Scott. . That's a nice jump in economy. What mileage did you get before and after the 275 install?

Mike

 

[hdtrukn]

Hey Mike

I stayed in the 15-17 range after 21-22, thats on paper not overhead computer.

I bought it new. got terrrible mileage and at 17k dealer replaced VP. No better.

Put another 50k on it getting 15-17mpg. Put in a set of RV275 injectors and stayed in the 21-22mpg. On highway watching my speed I have seen 24mpg. Thats staying about 62mph and with my 4. 10gear turning 2100rpm, thats what I have found to the best.

Of course that was when I dynoed 226hp, now I am near 500-550 mark and only getting about 18mpg. Wish I could get what my overhead is reading 25. 9mpg.

Scott

 

[EODMAR]

fuel economy

great info guys. I had to chime in and ask. Where did you get those injectors and did you do the work yourself?

 

[BTowler]

Mine were good for about 1 mpg. Mileage figures, gains and losses are so erratic, I have known people who have never seen over 17 mpg with a 2wd no matter what they do to it, and others that claim 24-26 mpg stock. Personally, my best was 19. 9, but is now hovering around 18 all highway, 14-16 city. What ever you do, don't expect big gains, but be glad if you do get them. And yes, the 35's are putting a big ding in your mileage.

 

[johncameron]

Hey MikeI stayed in the 15-17 range after 21-22, thats on paper not overhead computer. I bought it new. got terrrible mileage and at 17k dealer replaced VP. No better. Put another 50k on it getting 15-17mpg. Put in a set of RV275 injectors and stayed in the 21-22mpg. On highway watching my speed I have seen 24mpg. Thats staying about 62mph and with my 4. 10gear turning 2100rpm, thats what I have found to the best. Of course that was when I dynoed 226hp, now I am near 500-550 mark and only getting about 18mpg. Wish I could get what my overhead is reading 25. 9mpg. Scott

I'd say your stock injectors must have been WAY off to see a huge increase like that. I don't think the "average" increase is 4MPG for a mod like that. 0. 5-2. 0MPG increase would be more the norm.



JC

 

[MRose]

I just did a 570 mile trip and recorded it on my GPS for accuracy, 20mpg with my 35's on it. Best results 5X5 and 75mph, thats 1850 rpm w/3. 54's, 700pre-turbo and 8lbs level at 7600lbs. I've had 26mpg with my old 285's though, faster then I should drive but above 1800rpm it does net better numbers then at legal speeds.

 

[TARPONGUY]

Best mods for fuel economy

I've tried 275 injectors, Mach 1 EDM injectors, FASS, BHAF, ATS transmission, Edge EZ, 4 inch exhaust and none of them improved my mileage at all. The only mod that has increased my fuel mileage is the Smarty. On an unloaded fishing trip from California to Montana and back this summer I got a hand calculated over 20mph driving at 75 to 80 MPH. I would say that the Smarty got me at least 2 mpg. Just checked after 100 miles of all in down driving and got a hand calculated 15. 33 mpg. Hope this helps.

 

[ThrottleJockey]

The Marco 'SMARTY' Downloader has a fuel economy setting. Real crazy timing. For unloaded driving.

 

[VIPERBLUELX]

Well I just checked my fuel economy and got 12mpg this week unloaded with about 70% being highway driving at 80mph which is just under 2000rpms with my 35" tires. Something has got to give!

 

[BTowler]

That is probably close for your set up. The 35's offer a lot of rolling resistance, which will hurt your mileage. Most of the people I personally know don't get over 16-17 with 285's and 4wd, all highway.

 

[MrDiesel]

Well I just checked my fuel economy and got 12mpg this week unloaded with about 70% being highway driving at 80mph which is just under 2000rpms with my 35" tires. Something has got to give!

Remember your getting a little better than that if your speedo hasn't been corrected.

 

[Regcabguy]

Mods for mileage.

Go back to stock tires.

 

[VIPERBLUELX]

I had the dealer correct the speedo through the ECM after putting the tires on it.

 

[Cummins724]

The smarty will raise your mpg on the fuel saver setting... . some guys have seen 3-4mpg. Keep your tires full of air... . 35" tires can get alot of resistance when only a few psi low. Make sure that your brake shoes aren't dragging too. Another way is to get lightweight shoes or put a governor pin under the throttle pedal.

 

[jkidd]

MPG =timing...stacking Edge with ?

if timing increases MPG Why don't people stack boxes for added timing like an EZ with a van aaken? Is there a better stack for timing that would work with a juice?



I understand that the smarty/TST would be ideal, but I already have the juice.

The smarty does level 0 for unloaded use = more timing.



Does anyone know what settings on a juice or comp will add the most timing (not just fuel)?

 

[Cummins724]

if timing increases MPG Why don't people stack boxes for added timing like an EZ with a van aaken? Is there a better stack for timing that would work with a juice?



I understand that the smarty/TST would be ideal, but I already have the juice.

The smarty does level 0 for unloaded use = more timing.



Does anyone know what settings on a juice or comp will add the most timing (not just fuel)?

The main levels are timing & the sublevels are fuel. The adjustments bring in the timing at different times. I like 3x3 for towing, but my brother likes 3x4 which brings in a little more fuel. Level 5 is the most timing & 1 is the least. The smarty is the best bet for your truck... . stacked with the juice. You can't stack 2 timing boxes... . the added timing will cause damage to your engine. The smarty has the different levels for no timing etc. because it was designed to run with boxes like juice/comp. When you feel that juice kick in & all of a sudden take off... . around 2000rpm... this is the turbo lighting off & it throws you back in your seat. The smarty does this from idle..... it makes the power down low & you don't feel all jerky... . just smooth power throughout the powerband.