Dodge Cummins Diesel Forum banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

1 - 20 of 30 Posts

·
Registered
Joined
·
1,094 Posts
Discussion Starter #1
with the my current sig im seeing 800-900 egt at 1600 rom through town. this seems high. for good mpg's isnt it supposed to be about 600?? How can i help this matter. EGT's almost never hit over 1250 when WOT
 

·
Registered
Joined
·
4,943 Posts
with the my current sig im seeing 800-900 egt at 1600 rom through town. this seems high. for good mpg's isnt it supposed to be about 600?? How can i help this matter. EGT's almost never hit over 1250 when WOT
sounds about right, im seeing about 700 with my sig at ide say 60mph, or 1,600 rpms

with a free flowing exhaust your pyro's will be lower.



the lower the EGT's the better the mileage.
 

·
Registered
Joined
·
1,094 Posts
Discussion Starter #3
i have single straight stack
 

·
Registered
Joined
·
4,943 Posts
what gearing do you have in the differential? outside of that i think your pyro's are about right, the only other way to cool it down is to swap for a larger turbo.
 

·
Registered
Joined
·
1,094 Posts
Discussion Starter #5
what gearing do you have in the differential? outside of that i think your pyro's are about right, the only other way to cool it down is to swap for a larger turbo.
sadly im not sure. under the hood it says i have 4:10's. at 60 mph im hitting 2k rpms
 

·
Registered
Joined
·
1,094 Posts
Discussion Starter #6
i see guys saing there at 1650-1750 at 70 mph..my speedo is off but by how much??
 

·
Registered
Joined
·
4,943 Posts
sadly im not sure. under the hood it says i have 4:10's. at 60 mph im hitting 2k rpms
that sounds about right.

I have 3.55's and iim running 1,650ish rpm's at 60mph. i believe but let me find the dodge site and see what they say for 4.10's



47 automatic RPM table

here it shows allt he info you need, if not hit the back button and use the tire/gear calculators.
 

·
Registered
Joined
·
55 Posts
i see guys saing there at 1650-1750 at 70 mph..my speedo is off but by how much??
at 70 you're actually hitting 80-82 if you have 3.55's like me...thank the lord for cheap garmin's
 

·
Registered
Joined
·
55 Posts
sadly im not sure. under the hood it says i have 4:10's. at 60 mph im hitting 2k rpms
That sounds about right, my 97 had 4.10's and i was sitting at 2k-2100 on the highway
 

·
Registered
Joined
·
1,094 Posts
Discussion Starter #10
so how would i increase fuel milage? drive slow? lol but seriously lol
 

·
Registered
Joined
·
55 Posts
I keep mine at around 17-1800 on the highway, just because that is where you have a peak in the power curve (stock) which means that the engine is working most efficiently. With my 35's I see about 15 average, or 17-18 highway and 12-13 city. I also see better fuel economy while towing my 7k boat than unloaded. Not sure why, but I do.
For you put your comp on 5x5 and try to keep your foot out of it, thats about all I can think of. Your nozzles could be hurting more than helping if they arent extrusion honed (results in a finer spray pattern, and a better burn). How bad is your milage?
 

·
Registered
Joined
·
1,094 Posts
Discussion Starter #12
I keep mine at around 17-1800 on the highway, just because that is where you have a peak in the power curve (stock) which means that the engine is working most efficiently. With my 35's I see about 15 average, or 17-18 highway and 12-13 city. I also see better fuel economy while towing my 7k boat than unloaded. Not sure why, but I do.
For you put your comp on 5x5 and try to keep your foot out of it, thats about all I can think of. Your nozzles could be hurting more than helping if they arent extrusion honed (results in a finer spray pattern, and a better burn). How bad is your milage?
no better then 12. 12.5 if im very careful:(
 

·
Mopar1973Man.Com
Joined
·
26,259 Posts
with the my current sig im seeing 800-900 egt at 1600 rom through town.
Ummm... I see 300*F going through town... All towns in Idaho are 25 MPH limits...(expect for bigger towns like Boise)

But I got much smaller tires 235./85 R16 and pull 20-21 MPG daily...
 

·
Registered
Joined
·
1,094 Posts
Discussion Starter #14
Ummm... I see 300*F going through town... All towns in Idaho are 25 MPH limits...(expect for bigger towns like Boise)
YouTube - 300 pyro

But I got much smaller tires 235./85 R16 and pull 20-21 MPG daily...
YouTube - ScanGauge2 Trip


Would i truely be better off just saying heck with the lift/big tires and drop it a couple inches for alot better milage?
 

·
Registered
Joined
·
4,943 Posts
Would i truely be better off just saying heck with the lift/big tires and drop it a couple inches for alot better milage?
bigger tires always mean a degrease in mileage.

I run stock tires and find i have better pyro temps, but then again i see 400 at idle, and more like 500-700 driving in the city.


im just waiting for the 4inch free flowing muffler deleted exhaust, and a 4 inch turbo housing to go with it. maybe they won't just show up at my house.
 

·
Registered
Joined
·
4,107 Posts
what gearing do you have in the differential? outside of that i think your pyro's are about right, the only other way to cool it down is to swap for a larger turbo.
If max egt s are nt an issue a bigger turbo will actually raise low rpm/boost egts. Its the nature of the beast there. Im thinkin its those big tires and a laggy turbo doin the dirty to him. :confused013:
 

·
Registered
Joined
·
4,107 Posts
so how would i increase fuel milage? drive slow? lol but seriously lol
As mopar said get rid of those heavy swampers. My 02 gets less than 15 MPG in town now, never realized it was so bad because all my driving used to be hwy, where Ive hit as high as 25. :thumbsup: Drive by the pyro, EVERY diesel makes its best power for the amount of fuel burned at 550*, all engines in general do it at their torque peak. Get rid of that Hx 40, get somethin like a 62/65/12, they light @ 14 1500 rpm giving you useable boost down low.
 

·
Registered
Joined
·
1,094 Posts
Discussion Starter #18
As mopar said get rid of those heavy swampers. My 02 gets less than 15 MPG in town now, never realized it was so bad because all my driving used to be hwy, where Ive hit as high as 25. :thumbsup: Drive by the pyro, EVERY diesel makes its best power for the amount of fuel burned at 550*, all engines in general do it at their torque peak. Get rid of that Hx 40, get somethin like a 62/65/12, they light @ 14 1500 rpm giving you useable boost down low.


ive been debating a 62 for a while now didnt know that it would help fuel milage. my biggest problem is what tire do i go with?? this 5 inch lift is killing me lol. what good tire will work best IYO. Kinda care about how it looks, but if im getting 16-19 mpgs, doesnt matter really:D
 

·
Registered
Joined
·
1,094 Posts
Discussion Starter #19
also would this turbo be a step up, from the hx40?
 

·
Mopar1973Man.Com
Joined
·
26,259 Posts
ive been debating a 62 for a while now didnt know that it would help fuel milage. my biggest problem is what tire do i go with?? this 5 inch lift is killing me lol. what good tire will work best IYO. Kinda care about how it looks, but if im getting 16-19 mpgs, doesnt matter really:D
Ditch the lift too... The higher you stand up in the air the more wind drag you create. Wonder why ricers get 30-40 MPG they sit only 3-6 inches off the ground. (Less wind drag). wonder why reace car haul arse? (They sit only a few inches of the ground - Less wind drag) If it wasn't for the fact I needed my truck for offroad operation (gathering firewood) I would drop the height of my truck at least 6 inches and get low profile tires. I most likely cross the 30 MPG (or be really close to it!) if I did that...:party018:
 
1 - 20 of 30 Posts
Top