Some manufacturers claim you will get improved fuel mileage with their higher hp injectors. Surely this isn't the case with 100 or more hp injectors but I can see where this might be possible with lower hp ones. Please post your real world results after bumping up your injectors and what brand they are. Also provide what changes you possibly made in addition to the injectors so I can make a true comparison. I don't plan on doing anything other than possibly going to higher hp injectors if I have to change them. There's always a chance I may do a programmer later after this but probably not. I don't actually need any additional power and have a fast car when I feel the need for speed, but for the slight addition in price, I would do it versus replacing with stock injectors. My truck is an 03, 305hp NV5600. Thanks, I'm looking forward to your replies. Mr. moderator, please move this to the performance section if better suited there.

 

Only injector that this may happen is the 50hp injectors. I did not gain any or loose any with my current sticks. I did gain more power though.

 

Yeah, sounds too good to be true, maybe even with the lower hp ones, esp. since I drive with a light foot to begin with but as long as I don't lose, the extra power would still be nice. If I can at least come out even, I'll be happy. Thanks.

 

alan there was sort of truth to it. on the 04.5 up trucks a third injection pulse was added to aid the in-cylinder egr. to recover the mileage loss you had to change camshaft and several parameters concerning injection timing. the 35 to 50 hp injectors gave the best mpg increase. it worked by shortening the duration of the pulse allowing more fuel delivered near tdc where the most efficient burn is. go bigger and the spray droplets are to big and efficiency is down. no sooner than we changed our fleet to 50 hp injectors, Marty figured out how to get rid of the third injection pump and the 50 hp injectors are not needed, in fact it appears the stock is better than the 50. this only works with smarty or efi live that removes the 3rd event

 

So, Carl, do you think I will lose mileage if I upgrade to the 50hp injector on mine?

 

I upgraded to 50 hp injectors on my 03, my dads 03 and my 05. My dads truck is stock. It is way nicer to drive with the injectors. If you don't have a programmer the larger injectors advance your timing ( bigger holes = more fuel sooner) . A programmer does the same thing. If your milage is getting up there and you don't have added fuel filtration I'd get 40-60 hp injectors. You'll probably gain a little milage. The 03/04 trucks get the best milage to begin with. I went with DDP injectors, so far so good.

 

Thanks for the info. 03's getting the best mileage. Hmmm, imagine that. Less hp and gets better mileage. I think I see a connection.

 

Actually the 03/04 get better milage thanks to a better piston bowl design and a better cam. They didn't have to meet as strict of emmisions as the newer trucks. Actually my 03 has more power than my 05. They are modified similarily but the better piston/cam make it work better. Higher hp costs you mpg if you don't use it efficiently. If I can stay in 6 th gear and not downshift I can get better milage at 1800 rpm instead of 2600 rpm. Timing is retarded for emissions reasons so adding timing is more hp and better mpg. That's why bigger injectors help mpg the cost a lot more than a smarty jr though. I like my hp and fuel efficiency they are not mutually exclusive.

 

Ah, noop. It is the lack of 3rd injection event and better piston bowl design. The 04.5 and up are all emission motors 50 state legal.

 

I would have thought the 3rd injection event made more efficient use of the fuel and thus better mileage. I do see how emission regulations would work against the later models.

 

The third injection event is only under high load high rpm situations from what I have read. It won't really affect most guys milage I wouldn't think. The efi live and smarty programming removes it. The third event would cause more injector wear as they cycle more often.

 

alan fill out your sig so we know what your truck is. for the most efficient burn the fuel needs to be injected just after tdc into the flame of the pre combustion pulse, by taking the third pulse and moving into the second pulse you deliver the fuel where it is most efficient. by reverse engineering these engines and getting rid of the smog stuff your oil will now stay as clean as a 03, mileage better than a 03 and more power. my 06's is set up at 425 hp and 1,000 ftlbs torque, but you can not do this with just a programmer, hardware changes are needed. smarty jr is the only good programmer on the market, for the money this is the best way to go, you get 100+ hp and 20% better mpg for a fraction of cost of injectors. if you have a 06 up 5.9 then efi live by anarchy is best.

 

Thanks for the info. I'll post a sig.