Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Some deep thinking on getting Best MPG in a VAN

aardvarcus · 09-24-2018, 03:56 PM

Raceprops,

Didn’t notice you were in Arizona, rain probably isn’t as big an issue for you as it is in TN. I run Michelin Defenders or similar on all my vehicles now, while not a “MPG” specific tire, the return pretty good mileage but still have great traction. Yeah, hot rodders won’t build a low end torque engine, but you might find something related to towing or an RV engine build that would be close.

My first atypical engine is my 6.5L Diesel in my 1994 K2500 Suburban (NV4500, 4x4, 4.10). The atypical part is I am running it naturally aspirated not turbocharged. It is widely accepted on the internet that the engine would be more efficient with a turbocharger, however after much digging I have found evidence that suggests otherwise. Thus I run it naturally aspirated. Right now it is basically stock and is getting 24MPG based on the last four tanks, and should do much better when I upgrade the gearing (0.73 OD to 0.65 OD, 4.10 to 3.42 Gears) and improve the aerodynamics.

My other atypical engine is the 8.1L gas big block in my 2001 K2500HD. (8.1L, 4x4, Allison Auto, ECSB) The atypical part is I bought the 8.1 over 6.0 because I wanted MPG. It is widely accepted on the internet that the 8.1L engine would drink gas like it is going out of style, but mine gets 14MPG not towing. The mileage doesn’t drop much towing my equipment trailer when it gets more like 12MPG. That is based on many tanks hand calculated, not some instant readout going downhill. I have not heard of many other gasoline engines in three quarter or one ton pickups with automatic transmissions and 4.10 gears that do much better than this in real life conditions. I believe this is because the engine can lug along at lower RPMs while other engines would be downshifting. I would gladly swap the gearing to be taller, which is the biggest MPG hindrance on the vehicle, but I don’t put enough miles on the truck to justify the expense. Honestly if I could regear it to turn 1000 RPM at 55MPH I would.

You will notice that both of these are torque down low engines in heavy vehicles with the aerodynamics of a brick.

09-24-2018, 03:56 PM	#29 (permalink)
aardvarcus Master EcoModder Join Date: Apr 2012 Location: Evensville, TN Posts: 676 Deep Blue - '94 GMC Suburban K2500 SLE 90 day: 23.75 mpg (US) Griffin (T4R) - '99 Toyota 4Runner SR5 90 day: 25.43 mpg (US) Thanks: 237 Thanked 580 Times in 322 Posts	Raceprops, Didn’t notice you were in Arizona, rain probably isn’t as big an issue for you as it is in TN. I run Michelin Defenders or similar on all my vehicles now, while not a “MPG” specific tire, the return pretty good mileage but still have great traction. Yeah, hot rodders won’t build a low end torque engine, but you might find something related to towing or an RV engine build that would be close. My first atypical engine is my 6.5L Diesel in my 1994 K2500 Suburban (NV4500, 4x4, 4.10). The atypical part is I am running it naturally aspirated not turbocharged. It is widely accepted on the internet that the engine would be more efficient with a turbocharger, however after much digging I have found evidence that suggests otherwise. Thus I run it naturally aspirated. Right now it is basically stock and is getting 24MPG based on the last four tanks, and should do much better when I upgrade the gearing (0.73 OD to 0.65 OD, 4.10 to 3.42 Gears) and improve the aerodynamics. My other atypical engine is the 8.1L gas big block in my 2001 K2500HD. (8.1L, 4x4, Allison Auto, ECSB) The atypical part is I bought the 8.1 over 6.0 because I wanted MPG. It is widely accepted on the internet that the 8.1L engine would drink gas like it is going out of style, but mine gets 14MPG not towing. The mileage doesn’t drop much towing my equipment trailer when it gets more like 12MPG. That is based on many tanks hand calculated, not some instant readout going downhill. I have not heard of many other gasoline engines in three quarter or one ton pickups with automatic transmissions and 4.10 gears that do much better than this in real life conditions. I believe this is because the engine can lug along at lower RPMs while other engines would be downshifting. I would gladly swap the gearing to be taller, which is the biggest MPG hindrance on the vehicle, but I don’t put enough miles on the truck to justify the expense. Honestly if I could regear it to turn 1000 RPM at 55MPH I would. You will notice that both of these are torque down low engines in heavy vehicles with the aerodynamics of a brick.