I know my heavy 19.5's are dragging my milage down, but what else works?

The secret to getting good fuel mileage is to have a 12V truck with a 5sp transmission. 2wd helps too.

No doubt a good 12V will out do most of the new Cummins...

Has anyone put an electric fan in in place of the clutch fan?? I've read on some of the other forums about doing this but there doesn't seem to be a consensis on whether this is a good idea or not or if it helps mpg.Thanks

Has anyone put an electric fan in in place of the clutch fan?? I've read on some of the other forums about doing this but there doesn't seem to be a consensis on whether this is a good idea or not or if it helps mpg.

Thanks

No there is no gain...

http-~~-//www.youtube.com/watch?v=QeKndmCy_yk

I have installed the Flex-a-lite electric fans on my truck. Have to say that the marketing hype said you would save as much as 25hp and increase your mpg by up to 5-7%. This said 1+ mpg increase for me.I paid $495 for the kit with free shippingabout 4 years ago.I found it hard to believe that the viscous coupling fan could be consuming 25hp. But it has to be consuming some. But my interest was hoping to achieve some mpg improvement. I think the marketing hype also said something like quicker warm ups etc. The logic here is that the electric fans turn on with coolant temp setting and AC operation. So when you first start the truck in the morning the electric fans don't run, but the oem viscous fan will be running even when you start the truck and the engine is cold.Installation was pretty easy. Took me all day. I made sure all my wiring was tied and bundled and looked like a factory job.When I fired the truck up after the installation and went for a drive I didn't feel any increase in hp (I'm not sure how much of a hp increase it would need to be able to actually feel it. I know I can feel the increase of hp from a chip install that is advertised to add 50hp). What I did feel was a smoother acceleration when the engine was cold. But I was never able to validate any increase in mpg. I tried city driving, hiway driving and carrying my camper driving. Couldn't even verify a misely .5mpg increase. I have kept all mpg records from day 1 when I purchased my truck and can tell what impact (if any) that I have seen as I made mods or changed things from the original configuration.The install certainly hasn't caused any negative impact on my mpg or operation of the truck but I can't say there was any real benefit from going to electric fans.If you decide to go the route of the electric fan install you should be very aware that there is a gvw limitation for the truck when using the electric fans and that is 20k pounds. I am assuming this is because the electric fans ability to keep the truck cool under any greater load is limited.

No there is no gain...

Only reason I happen to say that is I removed the fan completely last winter and ran without a fan at all like ISX has been doing for the last 2 years. So far during my short test period of running without a fan I didn't see any gain or loss of MPG's either. As for the fan running when first started. Yes it will for a few seconds as you accelerate and then it unlocks and remains unlocked. Like in the video above.

Thanks for the replys.I meant to add this yesterday. I have heard of the mechanical fan freezing solid when below freezing and running all the time blowing cold air accross the engine making it take a lot longer to warm up. Have you had this happen? Will plugging in the block heater and putting a 60 watt light bulb ( turned on ) on near the fan over night prevent this??ThanksNew to Cummins. 2001 2500 4WD quad cab auto, 150 raptor, gauges on post and fuel pressure gauge, xzillar, put cover over kdp, did your breather mod - radiator was covered in oily dirt, k&n bhaf and intake elbow, 62 mm turbo. Am testing the iat fooler right now.

Thanks for the replys. I meant to add this yesterday. I have heard of the mechanical fan freezing solid when below freezing and running all the time blowing cold air accross the engine making it take a lot longer to warm up. Have you had this happen? Will plugging in the block heater and putting a 60 watt light bulb ( turned on ) on near the fan over night prevent this?? Thanks New to Cummins. 2001 2500 4WD quad cab auto, 150 raptor, gauges on post and fuel pressure gauge, xzillar, put cover over kdp, did your breather mod - radiator was covered in oily dirt, k&n bhaf and intake elbow, 62 mm turbo. Am testing the iat fooler right now.

No... I see temps as low as -25*F and never had a issue with fan freezing solid to the hub it always unlocks shortly after being started. Let us know how the IAT fooler works out...

Thanks, I will. I built a winter front and bolted it on in back of the grill also. The truck does warm up faster.

No there is no gain...

http-~~-//www.youtube.com/watch?v=QeKndmCy_yk

i just looked at your video and my fan is not that free at all. i will free spin when you shut it down but only 1 1/2 rveloutions. i would be afraid of sticking something in it while it is spinning. i do know i can here it when it kicks in and out. i dont see there being that little resistance on mine. i have never paid attention to it because it still cuts in and out depending on temp. is everyone elses the free or did you do something special to make it that free?

Mine spins free