Mpg question (optimual rpm)

I drove west on I-80 in WY yesterday. I was going 70 mph, and my mpg was fluctuating between 5.4 and 5.7. It was also very windy in some places. My average mpg is over 7.3 if I drive 62 mph. Oh, I don’t normally drive at 70, but the load I’m on needs it.

 

Wind will drop the mpg worst than weight .
Colder air has higher density , more resistance almost like in water need more energy to drive through it ( this is why we have inter cooler/ air to air on trucks, cool down the air to get more O2 at same volume/pressure) .
I stay around 62mph, if light i go 65mph; owning trucks with dpf for 12 years, i noticed that faster i drive more problems i had with emission , clogged dpf,doc, egr coolers, sensors.

 

Driving 62 is slow and may drive some people crazy, but I think this is all in their heads. Two of my OTR trainers drove 55 mph. I got so used to it that when I started driving 62 mph as a solo driver I thought it was fast. Some 2 years ago Stevens Transport trucks were governed at 62. After two years of experience, they bumped you to 66. Some very experienced drivers were allowed up to 70. Now Stevens moved their governed speed from 62 to 64.

The main reasons I drive at 62 is to reduce my fuel expense (which is my highest expense) and for less wear and tear on my entire equipment such as tires, brakes, and so on.

 

Hey 1st I'm not criticizing if you want to drive 52, 62 or 72 that's your decision.
I remember when the national speed limit was 55. Back then 62 was considered a good fast speed. Flash forward to today, if the speed limit is 65 and your driving 62. That's is considered a snail's pace. Not in anyone's head but in reality! AND no matter what reason you drive the speed you choose to drive. It wont change my statement about rpm at different speeds.

 

Can’t believe grammar nazis get so many thanks these days. Paccar doesn’t even make their own engine. The one that have Paccar logo on it is made by Dutch DAF. I think Paccar has a stake in DAF. I lost respect for Paccar because one of the 2 Peterbilts that we purchased new with Cummins engine had oil burning problem.
Paccar refused to fix or replace the engine saying that it was within Cummins specs.

 

It's winter.

I cannot be bothered to give a #### about fuel precision. I just fill at half tanks always all the way to the caps. Just need to have the company keep that fuel card full of money so I can throw it into the tank.

When winter is over that will be the time to try 2100 miles on 330 gallons.

 

PACCAR OWNS DAF

 

From 2010, PACCAR engines are manufactured for the US market in Mississippi