Try Hours

It's a Teams Life

Test from 58 mph to 65 mph

Feb 24, 2012 - 2:06:09 PM | By Linda Caffee

Do to the overwhelming response to Henry Alberts last blog and him slowing down from 65 mph to 60 mph we decided to join in on the test. Henry will drop his top speed to 60 mph.  We will pickup our top speed to 65 mph.


We are somewhat renowned for our phenomenal fuel mileage in our 2012 Cascadia powered by a Detroit Diesel DD 13.  We are often asked what our fuel mileage would be if we were to speed up from our customary 58 mph to 65 mph.


  While  Henry and us both get great fuel mileage and use many similar strategies there are also some major differences.   Up to this point Henry has achieved his stellar fuel mileage running 65 mph while we have achieved our phenomenal fuel mileage running 58 mph.


Henry runs 65 mph (the speed most trucks travel) to be of interest to people who read his blog. Our decision to run 58 mph is purely a business decision to run as efficiently as possible.


Both of us attend many truck shows and we are constantly asked how much it would affect our fuel mileage if Henry slowed down and we are often asked what would happen if they were to speed up. 


Well this is finally going to happen we are going to increase our speed to 65 mph and Henry is going to drop his speed down to 60 mph.  It is going to be interesting to see how these changes will affect both of our operations.


We are both planning on starting our tests on February 27 th with me updating my blog and the Henry will post an update on his blog.


Depending on what initial impacts we see will determine how long we will continue the exercise.  If the immediate impact is detrimental to our fuel mileage the test will be short because the bottom line is to see how we can improve our fuel mileage.


The following is our spec's for our 2012 Cascadia DD13

HP 370

Torque 1250 @ 1100 RPM

Rear End Ratio 3.21

Ten Speed Ultra Shift



To date our lifetime fuel mileage is:  11.1467


Henry has his spec's on his Blog

Please see Henry's blog for updates and to leave comments:

Henry Albert's Slice of Trucker Life Blog


Bob & Linda Caffee

Leased to: FedEx Custom Critical 


Saint Louis MO

Expediters 7 years been out here on the road 12 years


Expediting isn't just trucking, it's a lifestyle; 

Expediting isn't just a lifestyle, it's an adventure;

Expediting isn't just an adventure, it's a job;

Expediting isn't just a job, it's a business.

Comments - Tell us what you think below

24 Feb 2012, 06:31
24 Feb 2012, 14:30
This will be interesting. We have sped up a tad in ND and constantly idle and quite honestly I am too scared to compute our fuel mileage. Our first tank of idling was like 2.7 mpg. SCARY! Good luck and I can't wait to see the results.
Andy Johnson
25 Feb 2012, 00:08
When you run at 58 are you in direct or OD? Also, do you or Bob know anything about the new Allison 10-speed auto?

2.7? Ouch. Are you new to tracking fuel economy? Anything we can do to help?
25 Feb 2012, 08:28
Andy, when we are at 58 we are in OD and if we drop down to 55 it bounces back and forth from direct drive to 10th.

Wendy it is hard to imagine a 2.7 mpg until I think of all your truck has been through! The Freightliner Classic semi has went from a prima-donna over the road truck to an off road tanker yanker!

Wendy's truck has went to the oil fields in North Dakota and is now hauling crude instead of a reefer. The truck also now has a PTO and instead of shutting the truck of when they load or unload they have to raise the RPM's. They as well as their truck are going through a culture shock!

The Allison is not one of our favorite transmissions due to the fact it is fluid drive and takes away from fuel mileage. The new Allison is supposed to be more efficient. The Allison is also heavy.

Comparing the Allison to our Eaton Ultra Shift is interesting as the Allison was comparable to driving a automatic car. The Allison was also easier to back as I could back as slow as I wanted.

The Eaton backs faster and then appears to move forward slower. I have become accustomed to the transmission and have learned to back faster. The trick that works for me going forward is to ease into the throttle and let the transmission work.

Given a choice we would again go with the Eaton transmission.
David Wilmot
28 Feb 2012, 03:11
When we ordered our 2006 Volvo our salesman asked me how 'fast' we wanted to drive. I told him 65 MPH. When he came back with the specs. They had the rear ends at 3.70. I thought that was a little 'tall' but the short of it I trusted them. (the factory and salesman). The truck had an instant MPG gauge.When running at 65 MPH I could see better 'averages' that if I ran slower, say even as little as 62 MPH. And if I ran above 65 man there was a big drop in the numbers. When I traded that truck in the used truck manager questioned the gearing. My salesman (on our new truck)later told me they hooked up the computer 'thing' and ran the numbers and that truck had averaged 7.2 MPG from the time it was put in service.
That was a great motor, 565 HP Cummins,the truck pulled hills like a locomotive, POS truck and I hated the 18 speed Eaton Auto trans.
It just goes to show what good specs can do for you.
28 Feb 2012, 14:52
We are extremely happy with our truck and the fuel mileage we get. The Cascadia is even more then we expected even after all the research we did.

I really like the instant readout on the dash and use that to our advantage. We are having an interesting time with our test and you know as well as I we are given more than enough time to make our deliveries so speed is not an issue in most instances.

I remember the truck you are talking about as you did not keep it long. What is your new truck (old now) getting?
Rob and Jenni
29 Feb 2012, 00:05
This should be interesting to watch. We have a 2005 Freightliner Columbia with a 10-speed Eaton manual and a Detroit 60 475. As far as we can calculate, our rear ends are geared at 2.63. We are governed at 65 on the throttle and 60 on the cruise. We usually run our cruise at 60 and get about 6.6mpg. We've tried the test, too. 65? Fuel mileage didn't really go down that much, however, it also depended on the load weight, weather and wind conditions. Since we haul reefer, our loads can be upwards of 45,000. So that has a lot of bearing on the fuel mileage, too. Would like to see the specs on your studies in relation to weight, weather, speed and fuel mileage.
29 Feb 2012, 07:27
Rob and Jenni not knowing any of your peers and what they receive for fuel mileage your mileage might be really good. We know some people in reefer operations who cannot get to 6.

We first compare our fuel mileage to our peers and then we look outside our industry to see how we can improve our fuel mileage.

Rob and Jenni spend some time perusing Henry Alberts blog as he and us have spent a lot of time and effort on ways to improve our fuel mileage. Henry has went so far as to move his license plate so it will not be a wind drag.

This is a really good blog that Henry has written about his Journey to Great Fuel Mileage reat-fuel-mileage/

29 Feb 2012, 08:53
If you pull the panel below the fusebox on the Columbia, there is a sticker there with all your specs, ratios, etc. The rectangular panel below the fuse box in front of the passenger seat. It just pops out.
James Hamilton
29 Feb 2012, 14:00
Thanks for the info. How long before you get enough info on the speed change to know something. My company Cascadia 780 says it averages 8.2 . That has been consistent for three months. Loads vary but I did note one load at 80,0000 from Oregon to LA dropped a two month average .2 mpg.
29 Feb 2012, 14:16
James you can follow along on the saga here and I have links to Henry Alberts blog also:

Rob and Jenni
01 Mar 2012, 12:09
Thank you John about the info in the fuse panel. Actually, we had our truck hooked to a computer and it was found that we have 3.55 rear ends.

James that you?

Anyway, will be watching. We keep track of all our miles, fuel and fuel mileage constantly for a couple of reasons. One for performance and the other for the end of the year for tax reasons.
01 Mar 2012, 12:31
To follow along with our progress check out these two links to the blogs...
Dick Hedd
14 Mar 2012, 16:26
My 07 Columbia w/ C-13 is avg. 6.0 mpg pulling 43k out of Georgia, to Quebec.
14 Mar 2012, 18:32
Dick sounds like great numbers for where you run! Good Work
Rob and Jenni
09 Apr 2013, 21:06
We are now in a 2013 Cascadia and love it. We get on average 7.5 - 7.6 mpg. Our company pays us a fuel bonus based on our mpg, so it is a cool challenge to meet and beat their minimum.

We haul reefer trailers all the time and they are mostly loaded with 30,000 plus weight.

What we did find is, set the cruise (weather and road conditions permitting). Keep your foot off the throttle, and when you downshift, resume your cruise.

The cruise will know that you had it set on a higher speed, but when climbing a hill, you most likely won't reach that in a lower gear. If your RPM's get too high, then match your throttle to your road speed, pause your cruise, upshift and resume the cruise. Easy as that.

Works for us and it keeps our numbers up and money in our pockets each month.

We are now in a company truck since we gave up the O/O side of trucking. Too much legislature out there for the little guy to make it.
09 Apr 2013, 22:08
Glad you are enjoying the 2013 Cascadia and getting good fuel mileage. We sure had fun with this test but both Henry and us have moved back to where we are comfortable us as 58 him at 65.

Henry now has a new 2014 Cascadia with the DT12 Transmission you car read about over on . His record so far is 10.05 for right at 1400 miles.
20 Sep 2013, 08:16
Well not to start a fight but specs and trucks nature will detiremine where speed effects mpg. for instance my 1996 classic with a 500 Detroit tuned up and a gateless turbo gets 6 to 7 running 70 to 75 but if I drop her down to 60 to 65 she drops down to 5 to 5.5. running 3.08 rears and a direct 10 with tall rubber.

Also don't trust the trucks data tag to get your specs. Get dirty and check the tranny tag and rear end tags. I have seen new trucks have the wrong tag. Why someone custom orders the truck and never picks up but truck wont sell as setup so they drop in a different tranny or different rears.
Add your comment

Notify me about new comments on this page
Hide my email
Security Image: