Fuel Mileage

cerickson

cerickson

fullpull108
Joined
Feb 17, 2011
Messages
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I'm going to be purchasing efi csp-5. Was just wanting some input on what other members are seeing for fuel mileage after the excitement wore off with the added power? Going to be installing it on the wife's truck. Specs of the truck is this 06 3500 megacab dually 4x4 auto with 3.73 gears. Bone stock have fass 150 on it and will be putting edge cts for monitoring vitals. I know the tranny will need some work done eventually. But for a truck this big how much fuel mileage gain would I possibly see?
 
Some trucks get 15 and some get 22. No one can tell you what kind of mileage you are going to get out of it as none of us know how you drive or your truck. Is a couple mpg gain reasonable, yes it should be.
 
Thanks again phil. Sorry for the stupid questions. I was just wondering what other guys were getting for mileage.
 
In no way would I expect that mileage. 15-18 is realistic.
 
Alex what kind of truck are you getting 19-22 mpg? There's no truck in your sig. I would be happy getting around 18 mpg with a 3500 megacab 4x4 dually.
 
My dad's '06 3500 MegaCab SRW 4x4 48re with 4.10s on 35" tires is getting right around a hand-calculated 15mpg with a "Street" tune from Les at Silver Bullet Tuning for the highest, comfortable/safe HP with stock injectors and HE-351CW turbo. Les re-wrote the tune for a bit more mileage but we saw no change so we went back to the "Street" tune. Certainly happy with the power! Dad drives it for mileage the majority of the time but it just doesn't get much better than 15mpg. We've been discussing a free-spin kit lately since he's looking for more mileage. Every truck will respond differently.
 
My truck can get pretty good mileage but of course these trucks are not the best for strictly mpg. I hand calculate with fill to top of neck (have quick-fill kit installed on tank) and have stock size tires, 3.73 ratio so miles recorded is accurate. Driving 60 mph on cruise light truck has done best recorded 24.95 mpg. 65 mph same conditions 21.9365 mpg. At 70 mph drops down to 18.9 to 19.2 depending on wind and traffic etc. At 75 drops to 16.4 to around 17.6 is what I have seen again depending on traffic etc. Over 75 to 80+ just don't bother to check mileage...

These figures recorded after installing the SpynTec hubs and installing the new 5" aluminum driveshaft with 3-ton Spicers. So there is no driveline vibration at all and no interference from faulty unit-bearing front hubs. I am not sure if the EFI Live tunes are optimized for mileage at all. I had it set on hot street and exhaust was fairly smoky on any acceleration then changed to "medium" tune and less smoke but mileage has dropped slightly too. Now the autocal module seems to be broke so I can no longer do anything with it.

I definitely intend to get with Phil at Anarchy to acquire a V2 and enable some data logging so I can determine where the truck is and I have some BBi Stage 1s to install but haven't yet due to lack of tune support. Turbo is a small Garrett GT3782R which is a sweet little charger but moves about the same amount of air as a stock turbo. Stock fuel right now. Eventually will have a set of BB turbo twins (likely 3582 over 4202 GT wheels) and removing as much restriction as possible to enable greatest volume of air with minimal boost possible as my approach to building great mileage.

I think a lot of the difference in mileage is just how the truck is driven. The boost gauge is a good indicator of fuel use. When I have that gauge over 20 to 35 psi I know the mileage is right in the crapper.
 
Thanks guys for all the input. Nice to see some real world info on the mileage people are seeing. Will be after the new years before I get in contact with phil, but am looking forward to getting efi on the truck. Jimbo did you have to beef up the tranny in your dads truck or is he light on the pedal to save it? Commtrd same question did you do tranny mods?
 
Tranny was absolutely built. ATS converter, VB, input shaft and a Mag-Hytec double deep pan. The shop who built it is an ATS dealer. Knowing the ATS transmissions, they guaranteed they could build it better and about $2k cheaper than ATS's stage 6. That was done a little over a year ago. We haven't had a hiccup at all and it runs good!

Good to read the results from "commtrd" about the SpynTec free spin kit. As said before, we've been discussing it more lately. The kits can be somewhat expensive but you can't put a price on it if most of what you're after is mileage.

Hunted and pecked from a Galaxy S4.
 
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cerickson said:
Thanks guys for all the input. Nice to see some real world info on the mileage people are seeing. Will be after the new years before I get in contact with phil, but am looking forward to getting efi on the truck. Jimbo did you have to beef up the tranny in your dads truck or is he light on the pedal to save it? Commtrd same question did you do tranny mods?
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Yes I got Jeff Garmon's guys to do a re-build on my transmission to a Stage 2. I suspect the great mileage increase I got from the SpynTec was a result of the unit bearing hub on the passenger side going bad and causing a lot of drag. I just fixed that permanently. Most guys claim they only see a half a mpg from the install but there are other benefits to it too.
 
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cerickson said:
Alex what kind of truck are you getting 19-22 mpg? There's no truck in your sig. I would be happy getting around 18 mpg with a 3500 megacab 4x4 dually.
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I was getting around 21 with my bone stock 05 3500 Dually 4x4 with a six speed after I put a small edge box on it of 75 HP

:Cheer:
 
mobsquad120 said:
I was getting around 21 with my bone stock 05 3500 Dually 4x4 with a six speed after I put a small edge box on it of 75 HP

:Cheer:
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I have a friend with a SRW 04.5 truck that has the little EDGE pressure box. He traveles between Chicago and Lake of the Ozarks at least half a dozen times a year. His truck regularly sees 21-22 on his trip. His has 4.10's and some 34" highway treads and he usually runs 75-80 mph. I would not believe him till i saw it in person. Hand calculated.
 
That's what I was thing running 70-80 mph, with 4:10 gears. I was guessing the truck would get around 14 mpg?
 
If u get the anarchy tunes, put it on hot street. That's the tune I get the best mileage on. My street doesn't do near as well on mpg. Same with race. That hot street is the best of both worlds. Has great power and decent mileage. That's my 0.02
 
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