Need Advise

[CBari]

I Have Two Trucks One 04. 5 And 03. Both Get Excellent Millage Empty But The 03 Which Is Ho 3. 73 Auto 4x4 Drw (yes I Know The Worst Combination For Milage) Gets Between 7 - 9 Loaded Between 12000 And 15000# Of Gooseneck Trailer. Running 70mph. The 04. 5 Which Is 2500 Auto 4x4 3. 73 With The Same Trailer Running 75mph Will Get Close To 12mpg, Plus Handles The Load Better. My Question Is What Mods Should I Make To The O3 To Help It Mileage And Increase Its Power 10mpg Would Be A Realistic Goal For Me To Reach If Possible. The 03 Is Used Almost Exclusively For Towing And Occasionally 20,000 Plus For Short Hauls Of Hay Less Than 100 Miles But Hills Are Involved. I Am Very Cautious Of Mods Because I Went Through Two Motors In A 99 7. 3powerstroke With Only A 50hp Chip And A Lot Less Towing Weight Maybe A Max Of 10,000#s. That Was An Expense Truck. The O3 Has About 68,000 Miles On It An Is 7,000 Miles Into A Trans Rebuilt.

 

[SRadke]

A timing/duaration box combined with intake and exhaust would be ideal for a rig in that situation. You could do just the box but you could gain another 20-30 usable hp with the intake and exhaust. The standard TST program is excellent for a tow rig but you'll only be able to use the first 2-3 settings.



-Scott

 

[betterthanstock]

That's a difference of 50% in towing mileage!! Huge!! Make sure your TC is locking up on the freeway with the 03.

Also check fuel pressure under load. A bad lift pump, or leaky (internally) fuel pump, relief valve, or return lines at injectors could do that to you.

 

[Matt400]

Just curious. . is your 2500 a long bed and what size & brand of tires are on each truck?

Also at 75 mph I would assume you are using OD while towing, yes?

 

[CBari]

Just curious. . is your 2500 a long bed and what size & brand of tires are on each truck?

Also at 75 mph I would assume you are using OD while towing, yes?

THE 2500 IS QUAD SHORT BED AND IS RUNNING THE STOCK MICHELIN. THE 3500 IS RUNNING STOCK GOODYEARS THE HWY TREAD, I FORGET WHAT ONE THAT IS EXACTLY BUT IT IS THE ONLY HWY IN THAT SIZE THEY MAKE. BOTH ARE RUNNING IN OD.





O AND YEA I AM SURE THE TC IS LOCKING UP ON THE 3500. THE DEALER AND I HAVE WATCHING THE TRANS WHILE PULLING ON THEIR COMPUTER TRYING RULE IT OUT AS THE FUEL PROBLEM

 

[Matt400]

• Michelin's have less rolling resistance
  
• Short Bed weighs less
  
• SRW has less rolling mass and resistance
  

The OEM Michelin is the best tire for mpgs. I know you said the Goodyear is a highway tread but the M is still better IMO.

The other thing is tire size. Not knowing that, there may be a difference of RPM at the same given speed.



If you weighed each truck you might be surprised how much more the dually is hauling by itself.

 

[CBari]

Matt All Good Points But Why When Both Trucks Empty And Running 70 On Interstate Same Trip Same Fuel Fill. The Drw Will Get 19 And Srw Will Get 18. Both Hand Calculated On 450 Mile Trip.

 

[Matt400]

Dunno, you got me there. Maybe there is a (total) weight threshold where fuel consumption starts to drop off.

They are so close empty and maybe the same at 2000 lbs added, then still same at 5000 lbs added but 15K is a bunch of weight to pull and any weight reduction at that weight would be welcome for the 5. 9.



Imagine pulling that with your dually and then being able to unload 400-500 lbs, seems reasonable that the mpg would creep up 1 or 2 mpgs.

Thats just a guess but I would think your dually outweighs the shortbed by that much.



There might be something wrong with the dually, maybe not. 12-15K at 75 is a tall order for 10 mpg IMO.

 

[CBari]

Thanks For The Info



If I Go With Edge Juice/attutude Or Tst Which Has Better Safegaurds For Defueling In Order To Protect The Engine, If Say Wife Or Someone Else Is Driving And Not Watching The Gauges.