I have been chasing mileage and EGT issues since I bought this truck several years ago. I have been through 3 turbos, a p-pump, 3 sets of injectors and just about every cure I could find on the forums and by talking to shops. The truck has been in 6 different shops and the power has gotten better but the EGTs and mileage have never gotten better. For the last year they have actually started getting worse.
My last trip went like this: I left town towing a 5500# 5th wheel at night and hit the biggest grades running 55mph in 3rd and was able to manage egts below 1200° but the water temp was almost redlined by the top of the hills. The next day I towed 10,000# up a 5 mile long grade in the heat of the day I hit the hill at 55mph (2300rpm) and the EGTs hung right at 1200° driving by the EGT guage to try and maintaining control and dropping into 2nd when I was no longer able to keep it under 1250°. I eventually ended up sending the water over the redline 2/3 of the way up the hill. I pulled over to get the temps down and started again. I was not able to use 3rd at all without sending the EGTs sky high so I nursed it to the top in 2nd overheating the water again by the top of the hill. The next day on the way home I had the 5500# 5th wheel again and had nearly the same results on the hill as the bigger trailer. I could not even tow on the flats in OD without getting over 1200° and drove from Barstow to Vegas at 60mph or less. Pulling the 17mi long baker grade I had to drive in 2nd at 35mph the entire way with the A/C turned off to make it over the hill. The mileage towing 5500# was 9. 5mpg and empty on the highway is about 12mpg
Here is a list of the current configuration do give you a baseline to help.
Fresh motor with around 6000mi on it, ported head with 110# springs and fire rings, PDR quick spool cam, DDP 75hp injectors, 215hp pump, TST#10 plate in stock location, AFC housing in stock location with TST spring kit, timing at 17. 5°, 3piece exhaust manifold (cant remember which brand), 4" exhaust with straight through muffler, II 62/65/12 turbo. I had a 14cm housing the turbo and it made little noticeable difference. I also cut the exhaust in front of the muffler to eliminate a muffler issue and noticed no difference.
At this point I am completely out of money. I have been told that twins is the only way to solve the problem but my wife won't let me sell a kidney to pay for them. My primary concern is for towing performance. I would like to be able to pull the hills at any speed with a 6000# trailer. 15mpg would be awesome.
My last trip went like this: I left town towing a 5500# 5th wheel at night and hit the biggest grades running 55mph in 3rd and was able to manage egts below 1200° but the water temp was almost redlined by the top of the hills. The next day I towed 10,000# up a 5 mile long grade in the heat of the day I hit the hill at 55mph (2300rpm) and the EGTs hung right at 1200° driving by the EGT guage to try and maintaining control and dropping into 2nd when I was no longer able to keep it under 1250°. I eventually ended up sending the water over the redline 2/3 of the way up the hill. I pulled over to get the temps down and started again. I was not able to use 3rd at all without sending the EGTs sky high so I nursed it to the top in 2nd overheating the water again by the top of the hill. The next day on the way home I had the 5500# 5th wheel again and had nearly the same results on the hill as the bigger trailer. I could not even tow on the flats in OD without getting over 1200° and drove from Barstow to Vegas at 60mph or less. Pulling the 17mi long baker grade I had to drive in 2nd at 35mph the entire way with the A/C turned off to make it over the hill. The mileage towing 5500# was 9. 5mpg and empty on the highway is about 12mpg
Here is a list of the current configuration do give you a baseline to help.
Fresh motor with around 6000mi on it, ported head with 110# springs and fire rings, PDR quick spool cam, DDP 75hp injectors, 215hp pump, TST#10 plate in stock location, AFC housing in stock location with TST spring kit, timing at 17. 5°, 3piece exhaust manifold (cant remember which brand), 4" exhaust with straight through muffler, II 62/65/12 turbo. I had a 14cm housing the turbo and it made little noticeable difference. I also cut the exhaust in front of the muffler to eliminate a muffler issue and noticed no difference.
At this point I am completely out of money. I have been told that twins is the only way to solve the problem but my wife won't let me sell a kidney to pay for them. My primary concern is for towing performance. I would like to be able to pull the hills at any speed with a 6000# trailer. 15mpg would be awesome.