Engine/Transmission (1998.5 - 2002) How to boamb for MPG!

[Ray Torresdal]

INJECTOR EFFICIENCY

Has anyone actually tested various injectors for efficiency?? At 100 hp, 150 hp, 200 hp, etc. ? I know the larger injectors will allow you to make more horsepower, and that requires more fuel, but which injector will give the best economy in daily driving, or going down the interstate at 70mph, for instance. I keep reading that 275RV injectors will help mileage, what about the DD1's or DD2's? Or one of the other available injectors?



I would enjoy having the extra hp, but need to justify the expense, and added mileage would do that. How much extra hp can I justify might be another way to ask the question.



Ray

 

[MR V]

OK, I couldn't help in also asking the same question as above. I have spent about 10 + hours reading and searching. Do I want the RV275 or DD1. I want a little more HP, I don't tow, except a dirt bike trailer about 10 times a year. I don't want to lose any MPG, it would be nice to gain some.



Any advice would be appreciated. Thanks!

 

[Hohn]

no problem, mr V.



AFAIK, the RV 275 injectors are the only ones that people have reported considerable mileage gains. DD1 make more power, but I think the fuel mileage is the same as stock.



IMHO, the 275 injectors are the only ones in this boat because they're the only ones that have low enough power to where you aren't using it too much. The DD injectors are made from 275s (I think), and have more holes in them than stock ETH injectors. Atomization should be improved, but once you go past DD1, there is so much more power that you find yourself using it, and wasting fuel. I would guess that DD2 is about the point where the larger hole size (and resulting poorer atomization) offsets the fact that there are more holes.



IMHO, if you could drive a DD1 like you do stock, you would see mileage gain. Very few people can do that.



HOHN

 

[MGordon]

I installed my EZ about two weeks ago. It appears that I am now getting 2-3 mpg better mileage. It seems hard to believe. I'm going to continue and monitor this. Of course the real test will be when the camper goes back on!

 

[rspinks]

Not sure why but even easy driving with the Comp brings my mileage way down (no pump wire). Running on just the 275's improves mileage noticeably.

 

[MR V]

rspinks, what does the RV275 do for power in your opinion (both with the comp and with out the comp)? Thanks

 

[rspinks]

I found the power of the 275's was quite subtle, not "in your face" torque increase like the EZ around 1500rpm, more like a smooth power extension through the rev range. I like them, for $300US you get nice if not huge power, noticeably better mileage and small puffs of smoke if you get ahead of the turbo.



Edit: I mean small puffs of smoke with the Comp off, on 1x5 it will leave some impressive black clouds.

 

[MR V]

MGordon & rspinks - thanks for your input.



Any other input/advice welcome.

 

[Big White Beast]

As stated earlier..........

I think aerodynamics play a key role. I have a huge utility bed on the truck (3500) and it clobbers my mileage. When it was stock and empty I only got 10. 5 MPG. I even tried babying a tank or two with no gain. I added a 4" exhaust, EZ and BHAF and gained 1. 5 to 2 MPG. I firmly believe the EZ helps most on heavy trucks.



Anyway, since then I've done injectors, turbo, gear swap twice, transmission mods and tried every additive there is and all to no avail. MPG stays the same, the good news is it's way more fun to drive for the same MPG.



As I posted in another thread, for me to pay for all my mods with mileage I would have to drive this truck for 1,000,000,000 miles or more. Go for 275's an EZ and 4" exhaust and call it quits. You wont win any races but you'll have a very strong truck with better mileage.



Garrett



EDIT: On second thought you'll have no problems racing the Ferds and Chebbys.

 

[HC]

My experience with an HO running 275 injectors was that I lost somewhere between 0. 3 to 0. 5 mpg with an EZ, regardless of jumper setting. When I removed the EZ, I got maybe 0. 5 mpg better with 275's than my "pre bomb" mileage. I p-mailed many other members to get input on different injectors, almost every one who had tried both 275's and other injectors saw mpg gains with 275's but not with other injectors.



My driving is mostly light loads and below the speed limit. As load increased, the loss with the EZ became greater. All hand calculated, with lots of notes on average speed driven per tank, etc. , so the numbers are a fair representation of how one truck (mine) performed. As they say so often, YMMV.

 

[Steve Campbell]

Big White Beast said....

"As stated earlier... ... ... .

I think aerodynamics play a key role. "



I just installed 12 "Air Tabs" across the back of the top of the roof of my truck. Not very noticeable to the eye (more of a curosity than anything). I will see if they are noticeable to the pocketbook.

 

[JCyrbok]

DD TTPM

Anyone run the Diesel Dynamics True Torque Power Module (like an EZ) in the "timing only" mode? They claim in increase in mileage and was wondering if it was true. I know that a slight bump in timing can increase mileage but would it decrease power, etc. I think that Piers said that the increase was about 2 degrees in timing and would not cause "timing hammer" or increase head pressure.



Any thoughts or experiences?



Thanks

J-

 

[duaneparks]

I realize the original question involved an Edge EZ... so take my comments for what they're worth.



I run a Comp with the pump wire attached. Usually it's on setting 1x5 or 2x5 and I noticed a 0. 5-1. 0 mpg gain over stock with it on. When I added a Scotty II I didn't gain mpg, but I did get lower EGT's and more turbo sound ) ). Straight-piping the stock exhaust had no effect on mpg either.



Of course, when talking about mpg, driving habits also have to be discussed... so here are mine:



50/50 mix highway/city with shifts between 2K-2500 rpm, 70-75 on the highway, and around town I'm not easy on it.



I had considered the EZ when I bought my Comp, but figured what the heck... if I want access to more power, buying the Comp first was the way to go.



I only have first hand experience with a Comp, so don't get me to lying about other products...



Duane