Thoughts on 3.08 diff ratio

My mpg benefit at 55mph was better at 1350. I also didn't drop dead everytime a slight grade was had.

I could see 1100 on the flat land. But not when there's grades.

And even with a variable fan. You can't make it spin faster then the engine. So. Engine speed still makes a difference.

I don't know why you want the fan on all the time though. That kills your economy. Ever felt the difference in engine power when the fan kicks on and off? Specially if you got one of them fans angled enough they're really loud.

 

Variable-speed fan drive | viscous fan clutch.

Here’s some reading material for you. Talking about an old fan kicking on and off versus a new fan is footballs and peanuts.

 

Not sure. My old truck is an hour away from me still hauling milk every day and has to have over 800k on it by now.

 

I used to drag the steel bumper that was on my FLD before I put a Herd on. Go thru a dip and have dirt caked on the front of it.

 

Air drag at 70 mph takes about 3 times the hp as 55. Gears are not going to change that.

I have driven several trucks governed at 75 mph. 3406E 475s, 500 ISX to 500 DD 15. They all got about 20-25% better fuel mileage running slower. Boost gage tells the story.

Your mileage may vary.

 

Rolling resistance is a huge factor at speeds over mid sixties as well.

 

How do you adjust timing on a diesel?

 

No, that's fake news

 

Just had mine done under warranty, the OneBox was right at $10k itself, no labor, none of the other parts.

I wondered when they would get around to the computer controlling the viscous drives. Temp controlled viscous drives go way back to when air fan hubs were rare. I drove a 78 Mack with one.

On the high pressure common rail engines, the computer fires the injector whenever it wants. Injection pressure isn't dependent on a cam lobe or Bosch style pump anymore.

 

I know, it's common rail. Homeboy I quoted sounded like he was gonna twist a distributor on a ISX. Funny you should mention, I saw the other day it was either a/c compressors or alternators on the new rigs have viscous computer controlled clutches now. Mo Efficient.