Best Mod For Mpg Increase????

[TOY 2]

With diesel at $3.00+ MPG is becomming more important then ever :mad3:


I just got a 05 CTD with 6 spd. manual tranny. I got 12 mpg towing about 6k car trailer(75mph). 14.5 mpg empty(70mph).truck is still new(3k). I just added a edge EZ programer and milage went up about 3.5 mpg :eek: on stage 1. I went on a 340 mile trip today and on the way over pulling 6.5k car trailer I got 14.7 at 75 mph tach was at 2400 rpm. droped off a truck and on the way back I got 19 mpg towing a empty car trailer at 66 mph with the tach at 2000 rpm.

Question is what else can I do to increase mpg?? I think adding a littler taller tire so rpm's are a little lower at crusin speeds will help??? will K&N air filter help? or and exaust system? Would any of these mod's be worth the money for increased mpg? Don't really want to spend $1k for tires and increase milage .5 mpg :shaking: anybody have real world experance with this? Please post up milage,speed, if towing, weight ,and rpms of engine. thanks for the help :smokin:

[crashnzuk]

I just took off the 35s on my 91 and put the stock 235/16s back on. It was worth about a 2 mpg gain on my truck. It may not be such a big deal on your truck since you have alot more power than I do to begin with. Bigger tires suck power and fuel, not to mention you have to reset your speedo or calculate how far it's off. The best way to get good mileage is to keep your boost low while accelerating (like 10psi or less, empty), and drive as slow as you are comfortable with (try 70 while towing). Going slow and keeping your foot out of it will keep the mileage up and it's free.
Travis..

[rpm4x4]

Ive found that my rig has a sweet spot that it gets the best milage towing and empty. This spot is also where it tows the strongest so it all works out. My rig is a 99 dodge 24 valve 4x4 dually with a 5 speed 3.55 gears and 215-85-16 tires. If set the cruse at 72mph I will get 20mpg empty and 13 pulling my 14k goose. If I bump it up to 82mph It drops to 17 empty and 10 pulling that trailer. If I drive 62 I will still get 19 empty and 13 pulling the trailer but I will constantly have to shift down to 4th pulling the trailer.

I swapped up to 235-85-16 recently to fill up the wheelwells a little better. The results were disapointing at best. Empty all is well. Spedo is off a bit but even worse milage while towing falls off dramaticly plus I find myself shifting down a lot more. I just sold them to a freind of mine and am going back to the original size.

Mike

[crashnzuk]

Yup, bigger tires screw up your gearing. Although I think all of the new trucks have 3.73 gears. That said, a small diameter increase may be ok but I doubt it would return enough in fuel savings to be worth the effort. My truck likes 1800-2000 rpm for cruising, but it's an entirely different animal than yours.
Travis..

[NCtoy]

I just bought the exact same thing as you, and I've been getting about 18 mpg on the highway, and a little less around town. Haven't pulled any weight yet. I've got the 3.73s, what gear do you have?

[SolidAxleDurango]

Stop worrying about mileage. Just drive.

[TEX]

Drive 65 instead of 75. Get out of bed 15 minutes earlier instead of spending any money on mods. Cheapest way to save fuel & by far the most effective.


TEX

[sucmah]

I got the same truck and my milage sucks to. Is that edge programer one that you hook to the obdII port or is it a wire in chip? Did the milage increase on the overhead console or is this hand calculated? I went to 33's on my 05(3.73 gears, daimler 6speed) and my milage dropped a little. Dont have a choice though cause i tow in the sand alot. I need a wide tire.

[EHess]

With diesel at $3.00+ MPG is becomming more important then ever :mad3:
Question is what else can I do to increase mpg
gas saving device (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ru=http%3A%2F%2Fsearch.ebay.com%3A80%2F7993916387_ W0QQfkrZ1QQfromZR8QQfviZ1&item=7993916387) :flipoff2:

[MattS]

I just added a edge EZ programer and milage went up about 3.5 mpg :eek: on stage 1. I went on a 340 mile trip today and on the way over pulling 6.5k car trailer I got 14.7 at 75 mph tach was at 2400 rpm. droped off a truck and on the way back I got 19 mpg towing a empty car trailer at 66 mph with the tach at 2000 rpm.

Is that hand calculated or trip computer numbers? The trip computer is IMHO worthless. Putting a box on the truck usually makes it even MORE worthless.

[Eskimo]

Question is what else can I do to increase mpg??

Slow down, drive like there's an egg between your foot and the throttle.

[TOY 2]

I'm using the overhead thing for milage. I have check it by dividing fuel and milage and it was right on with the computer.

the chip pulgs in to the fuel pressure and map sensers. I haven't checked the milage manualy after I put the chip in

[Po' riggity]

Just drive it, and quit whining.. we all have to pay these prices, you aren't the only one.
Scott

[TOY 2]

no whining just looking for more information.

[ScottFJ40]

I agree with the guys saying slow down, it's hard to do, but the mileage gains are significant.

I can also back up the edge EZ claims. It gets better MPG on any setting, versus no EZ at all.

[dubbyx]

my 84 burb can't even begin to pull 8mpg in the city, but I can push 20 on the highway... running 32x11.5x15s and factory gears... engine has been massively modified, but I have no power because of the gearing...

I cruise empty at 78mph, and get 19-20, and 1200rpm... until I hit a hill and slow to 50 just to try and get up... pulling one of my trailers, I drop about 5mpg... empty or loaded

definitely don't expect larger tires to help. :(

[probuilt]

i agree with rpm4x4 mine seems to have a sweet spot too but they differ so much between vehicles that there is no real strategy for mpg...mark at tst recomends using egt guage as a kind of rich lean meter combined with seat of the pants feel...for instance if the truck is setup right there will not be a spike in egts or a lag either one could represent over fueling for the situation, gear, and boost...its kinda hard to express on a keyboard (so Flame away) but people that watch their egts know where that sweet spot is...bad news is after all of this and controling the way i drive mpg increased 7% empty and dropped 9% towing (but the truck did seem to haul better)

[MattS]

my 84 burb can't even begin to pull 8mpg in the city, but I can push 20 on the highway... running 32x11.5x15s and factory gears... engine has been massively modified, but I have no power because of the gearing...

I cruise empty at 78mph, and get 19-20, and 1200rpm... until I hit a hill and slow to 50 just to try and get up... pulling one of my trailers, I drop about 5mpg... empty or loaded

definitely don't expect larger tires to help. :(

His truck and yours have about nothing in common. I switched from 265's to 315's (32" to a 35") and got about 1.5 mpg better. Reason being is I can cruise in OD in the sweet spot of the CTD and maintain the speed I want. I needed to buy tires so I picked the size to best fit my driving. They didn't work the best in the mountains but I'm hardly ever in them so it was not factored into the purchase.

With both my 03 and 01 1800 rpm seems to be the sweet spot for the best mileage. Also picking up a little speed before hills and NEVER ever lugging the engine helps. Anytime you lug a CTD you get bad MPG, smoke and high EGT's.

If you have a overhead console with the instant MPG it's pretty easy to find the sweet spot.

[4x4not]

For a common rail dodge you can get a mild chip (such as a Quadzilla ZXT tow module). If you can keep your foot out of it they are supposed to be good for 2mpg

[Hendo]

i wish i got that kind mlage, i got a gas 5.7 gm utl bed towing my fj mostly frwy a few steep hills (grape vine ,168 hwy)9 mpg , i usually get 11 mpg,no trailer, tools ,loaded, mixed town hwy sometimes even sa good as 12.5 mpg w/no a/c
i got a ford 1ton van 460 fi only a 3 spd loaded with parts & tools 7mpg hwy, about 8 in the street , no overdrive, so you can see i was happy to get my 3/4 ton chevy trk. i may only go 40 mph up the grape vine but eh

[Raptorman57]

His truck and yours have about nothing in common. I switched from 265's to 315's (32" to a 35") and got about 1.5 mpg better. Reason being is I can cruise in OD in the sweet spot of the CTD and maintain the speed I want. I needed to buy tires so I picked the size to best fit my driving. They didn't work the best in the mountains but I'm hardly ever in them so it was not factored into the purchase.

With both my 03 and 01 1800 rpm seems to be the sweet spot for the best mileage. Also picking up a little speed before hills and NEVER ever lugging the engine helps. Anytime you lug a CTD you get bad MPG, smoke and high EGT's.

If you have a overhead console with the instant MPG it's pretty easy to find the sweet spot.


I'll agree with all of that.

I'm running a 01 CTD with the Banks Stinger kit. I bought it used with all the Banks goodies on it but so far I'm very pleased. I've drove stock CTD like mine and I can say there is an improvement in certain areas or RPM levels. When I bought the truck it had stock wheels and tires and IMHO they are a little on the whimmpy side for a truck this size. I went with a new 16.5 wheel and run 35's cuz a 35x12.50x16.5 is a pretty good deal cheaper than a 315x75x16 most of the time. So basically the MUCH better looking wheels paid for themselves when I bought my 2nd set of tires.

Going to the 35's did nothing to my fuel mileage. I averaged 19 to 21 MPG before the bigger tire and still average the same. I've figured it manually and watched the computer readout. The readout is off a touch due to the tire size so it in fact does read a shade less. Me and my father in law sat down and figured both tire diameters and the difference in distance traveled with both tires. It WAS ALOT of figuring and number crunching,but I figured it was the only TRUE way to figure what my actuall MPG was with the bigger tires. Just like Matt stated,I can now cruise in a better RPM range.