Autos vs Manual transmissions

Come on, don’t stop now. I am really starting to learn about charging systems from you. I wish I would have known you years ago when I was running flat braid ground, rf bonding, thin rolls of lead sheets for rf shielding my ecm, a motor maul stepped down from 24 volts and thousands of watts (less than a watt of reflect too).

 

Is the ecm what I plug this thing-a-ma-jiggy into? (pardon my language, I am not mechanically inclined)

And then it downloads a bumfangled tune into this weird looking motor so it can run correctly, provided the voltage regulator is functioning adequately?

 

Tell that to the trainees I get that rev a CAT to 2500 rpm (once, and only once, the second time they get brought back to the yard).

Companies put rev-limiters on trucks because most drivers these days don't understand that most diesels aren't designed to go above a certain RPM.

 

I've been a Class 5 (four wheelers) licensed driver since 2003. I've been driving truck since January 2015. I had about 30 minutes combined experience driving a stick shift in a car for those 13 years. Moving into the trucking industry, and being taught how to properly utilize a manual transmission, showed me the light when it comes to control of a vehicle.

Auto trucks offer little to no feedback to the driver, and take control of far too many facets of keeping the things on the road. The marginal increases to fleet-wide fuel economy isn't worth surrendering a 80,000-137,500 lbs vehicle to the whims of a computer.

Just because the technology exists doesn't mean it's a better thing to have.

Did you read the recent EPA report about pre-2007 diesel motors that found they performed better when properly re-manufactured than post-2007 emissions OEM engines? Or should we just follow your logic that because it's new, it's better?

 

I was just talking the other day about high revving engine brake in the automatic I drove Monday. It hit 2200 rpm on stage 3 and I cringed and knocked it off. I worry about valve spring fatigue in situations where the engine brake goes that high, since there are no mechanical safeties in place to keep from dropping a valve and people typically don’t test spring open pressure and closed pressure during overheads, they just replace during overhauls.

In this case, if you drop the valve, you risk damaging the head, the piston and the liner, plus machining and labor adding up to thousands of dollars. I am surprised there aren’t double valve springs like there are for racing applications, especially with so many inexperienced drivers out there. I personally don’t like to engine brake much past 1700 rpms.

 

Whenever I move an auto around the yard, I get in and put my foot through the floor where the clutch should be.

 

I've been shadowing our resident CAT guru as of late, as he's been rebuilding a few motors and been getting the low down on a lot of mechanical stuff in these motors I work with. Him and I have already agreed that if either of us win the lottery, we'll build two gliders together. He'll teach me how to build it, and I'll teach him how to drive it.

My CAT doesn't want to be higher than 1800 (I didn't have to be told this, I read the spec sticker on the side of the motor) and I don't often put the Jakes on over 1500, and will only take it up to 1700 if I need some heavier braking, or am getting near the bottom of a small hill.

I don't understand how people think these computers are smarter and better for this equipment than a human driver who has been properly taught how to operate it.

 

Consider a fleet of only 250 trucks. Fuel cost is $3.00/gal. Typical truck runs 12,000 mile/month. Base fleet mpg average with stick is 7.0 mpg.

Fleet miles = 3,000,000 per month
Base gallons fuel consumption = 3,000,000 / 7.0 = 428,571 gallons
Base fuel cost = $1,285,713

Now consider moving the fleet to auto improves fleet mpg to 7.5 (this is a very conservative figure)

Fleet miles = 3,000,000 per month
Base gallons fuel consumption = 3,000,000 / 7.5 = 400,000 gallons
Base fuel cost = $1,200,000

Difference = $85,713 month in fuel savings or $342/month per truck

Weight difference versus a like-spec'd 10 speed is nill but actually the auto is supposed to be about 119 lbs lighter

You call that a "marginal difference"? And that is only 250 trucks.

 

Keep 'em coming, these are good!

 

@STexan

Most drivers today get into this job because it’s just something to do for a living, they aren’t passionate about it. They didn’t grow up with relatives that drove trucks. If I was a fleet owner employing the average worker today, I would probably consider the auto because how little most people now know about mechanical things.

However, my company has about 700 trucks and probably less than 100 of them are manuals. I am in a manual, make multi stop runs in cities, up to 600 plus miles a day, and I consistently beat the fleet average by .7 to 1 mpg. I shift my rpms low, I only stretch it to 1400 in 9th and 10th and I keep my idle time low, not just for fuel mileage but dpf and egr issues. Most of our drivers don’t care about company trucks and put it to the floor everywhere they go. Our 2014 peterbilts had a software glitch where if you slipped the clutch, the truck would run 70 mph for a mile or so. We had trucks getting new clutches in them with only 60k on the odometer.

My dad has a t600 with a 120 inch sleeper running open deck, and he gets as good of fuel mileage as I do most times because we have tweaked the motor a little bit. 60 percent of your efficiency is lost under the hood due to inefficiency in the motor. Most companies leave the factory fail safe parameters in the ecm, and run it to 500k and sell off,