I have been driving diesel pickups since 1995 both juiced and stock. I trade often. I have had both GM and Ford. My current truck is a 2006 F350 with all of the Banks stuff on it. It seems that with each new truck I get the fuel mileage continues to escalate downward. I don't believe this is a brand issue but a pollution standard issue. I am contemplating starting with an older truck and building and installing a 6 or probably 4BT juiced, pre emission engine. I don't drive fast and don't mind if I slow a little in the hills. My goal is to get 16 mpg pulling my horse trailer at 65 mph total gross weight #20,000. Has anyone played with different combinations for fuel mileage?
Fuel mileage
- Thread starter sgs
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I agree that emmisions standards don't generally help the fuel mileage issue, but trucks have also doubled in hp over the last decade and a half. I'm sure that cost a bit of mileage too.
my dad's 83 Chevy Sub consistently got 27.5mpg on the highway (3/4 ton, 4x4, all stock). IIRC it generally stayed around 18-22 towing, but our towing was never a huge amount of weight - a small 2-horse trailer with one quarter horse in it plus gear.
I know my stock 94 IDI turbo will not do 16 with that kind of weight. I suspect your best bet would be a fairly late model dodge for fuel mileage - from what little I've read the CDR motor does better towing than the 12v which wasn't bad at all.
best of luck
oh, if you figure out how to get that kind of mileage towing let me know
my dad's 83 Chevy Sub consistently got 27.5mpg on the highway (3/4 ton, 4x4, all stock). IIRC it generally stayed around 18-22 towing, but our towing was never a huge amount of weight - a small 2-horse trailer with one quarter horse in it plus gear.
I know my stock 94 IDI turbo will not do 16 with that kind of weight. I suspect your best bet would be a fairly late model dodge for fuel mileage - from what little I've read the CDR motor does better towing than the 12v which wasn't bad at all.
best of luck
oh, if you figure out how to get that kind of mileage towing let me know
Thanks for the reply,
I also agree about the horsepower. My logic for thinking about a 4BT is as follows, If a class 8 truck can pull 80,000# all over the country with a 12 litre engine at highway speeds, why does it take 6 litre in a pick up to pull 20,000#? If you do the math backwards you come up with 3 litres.
Now if you assume 4 litres is the correct displacement for 20,000 # and do the math the other way you come up with 16 litres required for 80,000#. A Mack engine is 12, Cummins 11or 14, Cat 13 or 15, Detroit 12.7 and Volvo 12 or 16.
With my truck the way it is I can load up with horses and equipment, travel from Wisconsin to Wyoming and never loose .05 mph on any hill untill I get to Cheyanne. This is fun but not necessary.
When I traded my 2003 for the 2006 I thought this would be my retirement truck. I did everything I could think of to get fuel mileage. I went from a 4.11 to a 3.73, from a posi to an open rear end, Banks chip set at 3 frontal cooler exhaust, low restriction air cleaner, Taylor wing on roof, tilted every degree I could think of, traded the mud and snows for highway tread, and even bought a new aluminum horse trailer and lost 1,500 pounds.
Mlleage towing went from 10.5 t0 11.5. Very disapointing.
I have found quite a few people who claim 25 - 26 mpg in various vehicles but not towing. I talked to a diesel shop owner in NY who has one in a 3500 Chev and claims 25-26 but thinks I would be unhappy towing.
My memory tells me my old 7.3s got 14 if I drove decent. Back when fuel was cheap I drove fast. Now I don't.
So that is the goal 20,000#, 65 mph, 16 mpg.
Now who has a recipe for this?
sgs
I also agree about the horsepower. My logic for thinking about a 4BT is as follows, If a class 8 truck can pull 80,000# all over the country with a 12 litre engine at highway speeds, why does it take 6 litre in a pick up to pull 20,000#? If you do the math backwards you come up with 3 litres.
Now if you assume 4 litres is the correct displacement for 20,000 # and do the math the other way you come up with 16 litres required for 80,000#. A Mack engine is 12, Cummins 11or 14, Cat 13 or 15, Detroit 12.7 and Volvo 12 or 16.
With my truck the way it is I can load up with horses and equipment, travel from Wisconsin to Wyoming and never loose .05 mph on any hill untill I get to Cheyanne. This is fun but not necessary.
When I traded my 2003 for the 2006 I thought this would be my retirement truck. I did everything I could think of to get fuel mileage. I went from a 4.11 to a 3.73, from a posi to an open rear end, Banks chip set at 3 frontal cooler exhaust, low restriction air cleaner, Taylor wing on roof, tilted every degree I could think of, traded the mud and snows for highway tread, and even bought a new aluminum horse trailer and lost 1,500 pounds.
Mlleage towing went from 10.5 t0 11.5. Very disapointing.
I have found quite a few people who claim 25 - 26 mpg in various vehicles but not towing. I talked to a diesel shop owner in NY who has one in a 3500 Chev and claims 25-26 but thinks I would be unhappy towing.
My memory tells me my old 7.3s got 14 if I drove decent. Back when fuel was cheap I drove fast. Now I don't.
So that is the goal 20,000#, 65 mph, 16 mpg.
Now who has a recipe for this?
sgs
tgatch
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65 mph and 16 mpg towing??? Doubt that is going to be happening anytime soon. I tow a 12,000lbs 5th wheel and get 11 mpg and that is running at about 60 with a 3.73 rear end. Could probably do a little better if i had a manual trans.
I think your biggest enemy for fuel mileage is 325 hp and 570lbs-ft. I'd be willing to bet you could get a custom tuned SCT to detune the truck to say 250 HP and 440lbs-ft and you would probably see the mileage you are looking for.
BTW your comparrison to the big rigs isn't a fair one to our trucks. Our truck have Very peaky torque curves compared to a 15 liter CAT.
I think your biggest enemy for fuel mileage is 325 hp and 570lbs-ft. I'd be willing to bet you could get a custom tuned SCT to detune the truck to say 250 HP and 440lbs-ft and you would probably see the mileage you are looking for.
BTW your comparrison to the big rigs isn't a fair one to our trucks. Our truck have Very peaky torque curves compared to a 15 liter CAT.
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Also, a large amount of our fuel goes toward pushing air and I suspect that even though the weight of your trailer may be 1/4th that of a semi trailer the frontal area of your rig is probably not a lot less.
I have one of the "old" 7.3's (an IDI) and I know I wouldn't get 16mpg pulling your trailer. I don't even get that pulling my trailer which is a quarter the weight (but pushes a bit of wind).
best of luck, I really hope you figure this out - then I'll copy the formula
I'd be pretty happy with 16mpg pulling my 5k lbs motorcycle trailer
I have one of the "old" 7.3's (an IDI) and I know I wouldn't get 16mpg pulling your trailer. I don't even get that pulling my trailer which is a quarter the weight (but pushes a bit of wind).
best of luck, I really hope you figure this out - then I'll copy the formula
I'd be pretty happy with 16mpg pulling my 5k lbs motorcycle trailer
Thanks for the reply guys,
As I talk to various diesel shops the 4BT idea seems to be going away. I have worked in the trucking industry for over 30 years. I am learning now that these light duty diesels can't be modified to act like their big brothers. I am used to engines that cruise along all day at 1,400 - 1,600 RPM and develope peak torque at 1,200 and some even lower. I have also watched the industry loose almost 20% fuel economy when the 2002 emissions took effect. I just don't think we can expect much from a post 02 EGR diesel. The general consensus is that I could probably have the best shot at my goal with a 5.9 in line pump set to somewhere near 250 hp. I am a stubborn man and I am going to go ahead with this project. When, not if, I achieve my goal I will be happy to share the recipe.
sgs
As I talk to various diesel shops the 4BT idea seems to be going away. I have worked in the trucking industry for over 30 years. I am learning now that these light duty diesels can't be modified to act like their big brothers. I am used to engines that cruise along all day at 1,400 - 1,600 RPM and develope peak torque at 1,200 and some even lower. I have also watched the industry loose almost 20% fuel economy when the 2002 emissions took effect. I just don't think we can expect much from a post 02 EGR diesel. The general consensus is that I could probably have the best shot at my goal with a 5.9 in line pump set to somewhere near 250 hp. I am a stubborn man and I am going to go ahead with this project. When, not if, I achieve my goal I will be happy to share the recipe.
sgs
Brickman
Registered User
tgatch said:
Your right, the massive amount of torque compared to HP is what makes the liter difference in his computations.
My 3406e has 435 HP, but some thing like 1650 lbs of torque.
