Low mpgs / new injectors

[mjpbullz]

I have a 06 2500 that is completly stock with 220,000 miles and had a frend replace them with stock rebuilt injectors my problem is before my injectors went bad the truck got 20 to 22 mpgs now with the new injectors it will only get 17 max can someone please help? Thanks MontyPack.

 

[MChrist]

Are you hand calculating the mpg, or going by the overhead meter?

 

[mjpbullz]

By hand its 17. 5 computor its 15 to 17

 

[MChrist]

By hand its 17. 5 computor its 15 to 17

Is that highway mpg, or just around town, bopping around mpg? Also, did you do hand calculations before?



The reason I ask, is because just bopping around town, with no highway miles, I will sometimes get 12. 5 in the winter, and 14-15 in the summer. The best I've gotten is 21. 7 driving 65 on the highway for most of a tank. I could probably hit 22-23 if I drove 55, but that never happens.



If you didn't hand calculate your previous numbers, and only went by the overhead, that may be the problem. As injectors wear, they will let more fuel get through them, but the computer only registers the time they are open to calculate mpg on the overhead.



If you are getting 17. 5 with 80% highway and the rest is around town, that sounds like a pretty good mpg. Also, you need to fill in your signature with what type of truck you have (auto, manual, 2WD/4WD... ) so we have more info to go from.

 

[HBarlow]

If your new injectors are OEM replacements, not altered, and not leaking, they are not likely to cause any change in fuel usage. Wind, terrain, load, road speed, and summer vs. winter fuel will effect fuel mileage.

The overhead mileage indicator is of little value, it is a rough estimate at best.

Hand calculated with miles traveled divided by gallons used is the only way to determine fuel consumption.

If you expected a decrease in fuel consumption and an increase in fuel economy with new injectors you were probably mislead.

 

[Bill Weber]

mjpbullz: I log every tank of fuel & calculate my milage periodically. A 1 tank calculation is meaningless. There can be too much variation. Average at least 5 tanks before drawing any conclusions.

Bill

 

[cerberusiam]

had a frend replace them with stock rebuilt injectors

That is likely the problem if you have been hand calculating before\after and the conditions are the same.



A lot depends on your truck configuration and the type\speed of driving you do. A 4x4 at 55-60 mph in the right conditions will make 21-22, a 2x4 will do it more often. Calculation comparisons across months and weather conditions also will not match. You need apples to apples comparisons on all the conditions to be accurate.



The 17 your getting now does not sound bad for an average.

 

[mjpbullz]

Thanks to everyone that replyed I asked this on another board and got 0 replys I will go through a few more tanks and see what iI come up with. The truck is a 4x4 ,auto an d I useually set the cruise at 65. Thanks again Monty.

 

[MChrist]

Keep us posted. Also, are you in an area where they switch to winter blend fuel? Cold temps will also drop your tire pressure a bit. Do you have a 3. 73 or a 4. 10:1 ratio? All those things will affect your end mpg. If in a cold climate, do you let the truck warm up for quite a while?

All factors.

 

[AH64ID]

Based on the high pressure the injectors wear as you drive. Essentially it's the slow road to honing them and by they time you have 200K miles on them they are closer to a 30-50hp nozzle, which actually yields better mileage than stock nozzles.



I would also check you overhead and calculations, its very very rare to have the overhead indicate worse mileage than you are getting, usually its 15-30% high.