There always seems to be much debate over the subject of “what is the best speed to operate while still being the most profitable”.

Many factors go into finding the correct balance of speed vs time. First, freight rates are generally paid by the mile. This is the same as piece rate…the faster you drive, the more money you make per hour. I did some calculating at 60, 65 and 70 mph with a fuel cost of 3.70. I figured on fuel mileage varying from 6.5 to 7.5 and revenue per mile ranging from 1.30 to 1.90. I based the fuel mileage variance per speed at the universally accepted rate of one tenth of a mile per gallon, per mile per hour of road speed. I don’t like this accepted rule due to the fact that fuel consumption vs speed changes on a bell curve and not a straight line. Each mile per hour consumes fuel at a greater rate than the mile per hour before it. The difference in fuel mileage from 65 to 70 is much greater than the change from 60 to 65. At this point, I would encourage you to figure out what your fuel cost is per mile and per hour at any given speed. Next, figure out what your revenue is per mile and per hour. Minus your fuel cost per hour from your revenue per hour and you’ll find that in all of these cases, its more profitable to drive faster. This is an easy equation which leaves us to think that driving faster means higher profit. However, there are more factors to consider before making our final analysis.

As we mentioned earlier, fuel mileage changes on a bell curve and not on a straight line. Remember the faster you travel, the higher the average is between your cruise speed and your average speed. I’ve found that when I drop to 5 mph on my cruise speed, I typically only lose 2 to 3 mph on my average speed for the day. The reason for not losing the total 5 mph is due to not having to slow down as often for traffic which keeps my speed at a steady pace.

Another factor in this scenario is the tire life of the truck. Tires are a major cost in your trucking business. Tire speed creates heat and that heat reduces the life of the tire. Also, speed reduces the load capacity by 4% from 65 to 70 mph. Running over 70 mph reduces the load capacity by more than 12%. A change from 55 to 75 mph can reduce a tires removal mileage by 10% to 30%. A higher speed also distorts the tread of the tire causing irregular wear. Finally, a higher speed reduces the impact resistance to rocks and potholes.

Driving faster also reduces brake life. This is due to more frequent use of the brakes as you encounter slower traffic. Higher vehicle speed will cause increase temperatures to brake rotors or drums. The result of this action will reduce brake life.

The last factor I want to cover is increased use of fuel is directly tied to engine and component life of your truck and trailer. The more fuel you burn per hour, the quicker you wear out your engine, transmission, actuals, suspension as well as many other components of your truck and trailer. Fuel use is a good measure of work performed by your equipment. Think of fuel use per hour as a wear rate per hour.

Now that we have all cost per mile figured, let’s finish this equation by figuring how it affects our revenue. Will driving faster gets you an extra load during the week? Every day when picking your speed, you need to decide will it make a difference in your revenue? If you arrive at a shipper/receiver an hour after they close, there is zero benefit to driving faster. In contrast, if driving faster on your trip causes you to arrive at your destination earlier and your able to load/unload and not be hung up for an entire weekend, then the faster speed would be worth it.

When making your daily decision in regards to what speed you are going to run, you will want to consider all the factors we just talked about in order to maximize your profitability. In closing, I’ve found for my operation that 62 to 63 mph on average has provided me the best balance for speed and operational costs for my business.


 

Comments (10)

Henry Albert

Henry Albert is the owner of Albert Transport, Inc., based in Statesville, NC. Before participating in the "Slice of Life" program, Albert drove a 2001 Freightliner Century Class S/Tâ„¢, and will use his Cascadia for general freight and a dry van trailer. Albert, who has been a trucker since 1983, was recognized by Overdrive as its 2007 Trucker of the Year.

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I've been typically running at cruise of 60mph, but on one recent trip poor planning ( on my behalf) had me running the last 500 miles of a trip from Winnipeg to Laredo at 65mph. My ELD had me running short on weekly hours and with a zero return at midnight, I was forced to bump up the speed to make onetime delivery or being forced to layover a full day to recover hours. Typically tho I rarely need to run faster than 60.

July 20, 2014 13:16:02 PM

Kurt ,
I agree with you and make this decision on a daily basis as I am the driver and the owner . Sometimes I cruise faster because there is simply something I want to do on a personal basis such as ... Have time to go on a walk , see a movie or get home earlier so I can spend time with my wife and son . With that being said I also slow down when there is something to be gain by it . I have found going slower 80% of the time works the best for my operation . So as I stated in my blog it is a daily decision for maximum profitability and quality of life as well . You brought up a real good point which was not addressed in my blog . Thank you for the comment .

June 20, 2014 9:24:53 AM

The one factor I have never seen anyone try to put a dollar figure on, or calculate, is what is an hour of a driver's time worth? What is an hour of log book time worth? (And those are two very different numbers.) In the manufacturing industry they are capabale of figuring out the cost aspect of labor if they want to make more widgets, by either paying overtime, or hiring more help. As drivers our total available working hours are a fixed quantity, short of adding a co-driver, so the only variable to increase productivity (without changing equipment or weight rules) is to go faster. Yes I agree with all of your costs of going faster, but over the course of an entire calendar year, what are the differences either in productivity or revenue generation AND costs/value of the driver's labor? None of the big fleets ever entertain this kind of thinking, perpetuating the driver's time is "free", and why they think going to an hourly pay rate would be disastrous for them.

June 20, 2014 7:25:04 AM

Henry, good points! Are your trucks governed, and, if so, at what speed?

June 06, 2014 16:02:01 PM

So the big fleets were right the whole time. I see most of them around 62 or 63.

June 06, 2014 12:16:27 PM

I rarely need to speed up. I won't put myself in a risk (speeding, or dangerous). It is usually caused by time lost in Chicago. Then it usually to get to a spot before my ELD/HOS runs out of hours. It is most likely about getting in on time for a 34 hour restart. If I don't speed up, I could come up short on hours the next week.

June 05, 2014 18:07:53 PM

Jackie ... I agree with you on the time management and I rarely have been put on the position of needing to speed up . I also used to have a run in which there was the possibility of turning three rounds instead of two . It all came down to one hour of this was going to happen . The third round increased my revenue by over 2800 dollars a week . Right after picking up the third round time did not matter as much and I would slow back down to 60 mph .

June 05, 2014 9:51:10 AM

It's not always the best decision. The owner operator needs to figure out which way works for them. Speaking personally I have never had a load in the past 7 years that I had to speed up for. It always came down to time management. All I can say is if you have to speed up make sure the pay will compensate for the added fuel cost. It all comes down to knowing your numbers. Over half of the owner operators don't know their numbers at all. You can't make an informed decision without all the info.

June 05, 2014 7:23:16 AM

As one of the 57 - 58 mph ers this equation has not effected us as we have delivery times that are in 15 minute increments. Usually being early is not an option so we can concentrate on speed. Great points on looking at our own operations and deciding what is best for each of us to make the most profit.

June 05, 2014 5:12:25 AM

I agree. Planning is key, and knowledge is power. There is no law that we have to drive the same speed every day. I wonder how ELDs will effect the 57 mph ers

June 05, 2014 4:54:41 AM