Whats up with 62 mph?

That is really funny.

You are saying that you are at a disadvantage because you have to replace tires every 10 months instead of 12, even though you run the same amount of miles on those tires?

While you may need to replace them sooner, you also made the $$$ to do it more quickly.



As to another poster that equated fuel mileage strictly with engine RPM, saying that simply running at higher RPM's used more fuel - you really need to learn something of engine dynamics.

Change the lift and/or duration of the valve timing in any engine and just see what it does to fuel mileage at any given RPM.

I had a car that actually had better MPG running at a steady 90 MPH than it did at 65. The engine dynamics were such that it preferred the higher RPM.
So, I swapped out the rear end for a higher gear ratio. I went from a 3.08 to a 4.11.
I gained both acceleration and fuel economy in one simple step - by keeping the engine RPM's in a more efficient range.

I could also have changed the camshaft to one that had a more favorable torque curve lower in the RPM range.


There is more to fuel economy than simply how fast the engine is turning.

 

I tried to make that point 4 days ago. Not a single one of the naysayers could come up with anything to say about it.

 

I can give the "less wear on brakes" argument credit.

But this is grasping at straws now.

Tire heat comes from improper inflation provided you have tires that are spec'd properly for the loads you are running. Tire speed ratings are not going to change enough from 62 to 67 for that to even be a consideration.

I'd even give a LOT more credit to the fact that after you reach 60 mph, you REALLY start to have an exponential growth in drag as you reach growth. With 60 mph being the most efficient speed to drive at for wind resistance without reducing your speed to the point you truly are a road danger.


It's getting to the point it's just time to agree to disagree on running 62 vs 67.

But hey, this will be argued as long as there are trucks. It hasn't changed much in 21 years really.

 

Proper inflation and rotation has more to do with tire wear then the speed of the tires.

I get just as many miles out of the tires as our slow pokes do. But then I don't use a thumper to check my tire pressures either.

I am not worried about brakes because I downshift. My brakes usually last much longer then most of the guys in our fleet.

Drive train wear comes from people hammering the throttle in town and while trying to get going as fast as possible. I don't hammer on the truck to get it up to speed. Well I try not to but this bridged motor requires higher rpm to pull the gross weights that I pull. It is that or the exhaust temps and engine temps will climb out of site.

By running faster the 55 or 62 or what ever, the fuel costs are just slightly higher but I am getting more done which is more then making up for the slightly higher fuel costs. The bosses net income for the truck is higher when I run faster then if I run slower.

I have a slightly different job then most. I HAVE to run 660 - 710 miles a day, Then add our loading and unloading and other on duty operations. I am pushing hard against the 14 hour clock. Me slowing down would create a huge issue as I would be maxing out my 70 way to fast and not getting any miles or loads in per week. Which would leave me sitting more trying to get hours back.

Remember that not all of us have 3 days to put on 1300 miles.

Moosetek, I am not saying I am at a dissadvantage. I am saying that I am getting just as much done and the same amount of miles, just in a much shorter time frame.

If I try to break it down into an hourly pay. I am making far less money an hour by running slower then if I am running faster. Also it is not really costing the boss much more money per mile by me running 68 mph vs 62 mph or slower. He gets an extra load or possibly two loads a week out of me due to running 68 mph which means he has grossed between 1000-2500 dollars a week more depending on the pay from them loads. When he grosses more money then i get more money for the amount of time I am on the road. Which can mean a difference between me only making 600 dollars a week to me making more then 1000 a week.

 

Cattle loads pay that much?

 

You guys wouldn't like working for my employer then. Our trucks are governed at 59. There is 1 truck we have that'll do 65. It's also the oldest truck in the fleet and rides like a washing machine on final spin.

 

If you're pulling into a receiver 10 hours early - with a hard and fast appointment system, you're going to sit a minimum of 10 hours before they either assign a dock door or get around to touching your freight. There's no detention paid for that time either.

That's sitting around time. If you're running at 65 to get there 10 hours early, you just spewed quite a few dead presidents out of your exhaust stack in order to watch the traffic in the yard a nd nothing more. Now you can whine and wheedle your way into an early unload sometimes, but its a 50-50 proposition at best if you can't get the appointment moved up in the first place.

 

Yes. And $4 is on the low side..

 

Sounds like bad planning on someones part.....

It sounds like a lot of you guys get stuck with situations like this? Sucks to be you and I can now understand why you have to get great fuel mileage to make any money.

 

That's ridiculous. How many days would you have to run at 65 mph to get there 10 hours early ? Our drivers have mostly dedicated runs. We get to the receiver no more than 2 hours early and sometimes get unloaded right away. Then we bring the trailer to our home terminal and spend the extra hours at home.