New injectors bad mileage

[mitchC]

hello I had new BD 60 hp injectors installed in an otherwise totally stock truck with 220000 miles and my mileage fell 5 mpg. Hand calculated. Any ideas as to what happened or is this just the cost of the more powerful injectors.
I’m no hot Rodder and haven’t changed driving style at all. Thanks for any feed back.
06 3500 Auto QCab 4x4

 

[MarkEagleUSA]

Everything else being equal, the new injectors spray more fuel so a hit in MPG doesn't seem unreasonable.

 

[cerberusiam]

Badly formed injector nozzles and incorrect injector setup, typical problem with substandard injectors. I have gone 50 and 90 HP on injectors with same tuning and gained mileage over stock. CR injector building is an exact science that few have mastered, good enough is really not good enough.

 

[TCDiesel]

You don't gain mileage with injector change outs on Avg MPG, ther're may be sweet spot for maybe .5 You can't change the laws that governor the earth, It will take this much BTUs to make this much power to move this object. 5. MPG loss are you sure? If you use the additional power you may loose .5-1. but 5. Hmmmmmm, If correct and confirmed you had better get replacements ASAP.

CR Injectors need precise building and Calibrations just as Cerb stated.

 

[Tuesdak]

Any fuel leaks? Oil level good? Pouring black smoke out the exhaust?

Weather has changed possibly headwinds, but, the second I turn on the AC my MPG drops from 21 to 16. BBi stage 1 hasn't changed my MPG much, but, it's tuned for low smoke.

 

[mitchC]

Any fuel leaks? Oil level good? Pouring black smoke out the exhaust?

Weather has changed possibly headwinds, but, the second I turn on the AC my MPG drops from 21 to 16. BBi stage 1 hasn't changed my MPG much, but, it's tuned for low smoke.

hello no smoke oil level seems ok I’m using the ac a lot

 

[TCDiesel]

Pull OA and see if the fuel % is higher then normal.

 

[AH64ID]

High mileage stock injectors in good shape are often able to provide additional mileage over new stock injectors, but a 5mpg hit is pretty big.

I'd be checking for proper torque on the cross tubes, for fuel in the oil, or for any other signs on a leak (internal/external).

 

[AH64ID]

Everything else being equal, the new injectors spray more fuel so a hit in MPG doesn't seem unreasonable.

Just because they can spray more fuel doesn't mean they are always spraying more fuel. Quite often larger injectors can atomize better so there is a small bump in efficiency, as well as larger injectors can keep the motor in the higher timing cruise profile longer.

Badly formed injector nozzles and incorrect injector setup, typical problem with substandard injectors. I have gone 50 and 90 HP on injectors with same tuning and gained mileage over stock. CR injector building is an exact science that few have mastered, good enough is really not good enough.

If there isn't anything wrong with the install I would suspect this! 5 MPG's is huge, and if the install is good it points to poor atomization or other issues which can lead to catastrophic failure.

 

[mitchC]

Number 6 was leaking at the cross tube connection. Are going to replace the lines and retorque all feed tubes. Will chime in when done. Thanks for all the input.

 

[AHill100]

I just installed a NEW set of Bosch injectors. They work great, but mileage readout on the overhead console dropped to 16 and with the previous injectors it read 19-20 on average. I did not have a hand-calc measurement to use. AH64ID said something older stock injectors do better with mileage. My originals had 122,000 on them but had started to white smoke at startup a bit and subjectively felt down on power.