Mpg

Have you used progressive shifting?

 

You'll have to experiment and find the sweet spot on your own. If your getting 7.3 and idling,.. id say you are pretty close.

Cutting back on idling will increase your mpg substantially. I have a CAT C15 and can average 6 - 6.5 by not idling.

Hurst

 

7.3 - 8mph? Pretty good not a lot of upside from that. It sounds like your truck is rigged and running very well, so maybe you can find some driving techniques that will keep you up around 8mph? Actually, I did mph research on my DD60 14L for almost 2 years, got up to about where you are, I kind of just drive it now. I'm happy with 7.5 - 7.8mph average all loads, all conditions.

 

I drive a Volvo VNL 780. 455 horsepower, 3.08 rears, I-shift. APU. Suc ks going over the rockies but 8.7 overall mpg. Made for flat country. I keep it shining because, chicks dig me.

 

The cost of Idling goes beyond the fuel factor. it adds hours onto engine run time. Simply the engine wear is escalated by sitting at idle speed and we all know that oil pressure is lower at 600 rpm which means the upper cylinders receive less lube. Also idling breaks down the oil, resulting in varnish. So there is a relation to the engine time compared to mileage.

The cost of fuel is a huge factor. again idling can cost you not only in overall mileage, but in daily consumption. what is your average cost per day for idling? 10 hours at .8 gallons per hour = 8 gallons @ current market price $ 2.37 dollars national average or about $19.00 per day depending on actual use. There may be higher fuel prices that would directly affect your daily idle cost.

Now you must consider driving habits....each driver manages fuel usage with his or her foot. When it comes to squeezing more out the bottom line regarding fuel expenses and or the average MPG. there are ways to save $ big dollars over a set time period as in monthly and annual fuel cost reporting. Controlling cost of operations has a positive impact the net profit of any business.

Fine tuning the budget. Knowing where you are today at the current rate of consumption, you can add to the bottom line before taxes how much profit based on historical income and expenses. Budgeting and forecasting is one way to set a realistic and attainable goal that you are capable of achieving. This requires you to report controllable expenses on a daily basis so you don't wind up blowing it at the end of the month. There are programs for computers that can track your cost and calculate a running average as you go. A weekly recap helps you foresee where you are and what you will have by the end of the period. A Period could be monthly, quarterly, semi-annual and annual reporting cycle.

In the real world, we all know that idling is a factor in fuel cost and on hot or cold days we all have to do what we need to to say comfortable and rested ready to return to on-duty after a break in the sleeper....

If you want to save $ and increase your average MPG from 7.0 to 7.5 you can figure out where to make the adjustment, be it in driving habits and other areas. Try running at 1400 RPM top gear on the hwy and use progressive shifting while also minimizing idle time, can and will effectively lower your fuel cost at this time.

If you don't like the idea of driving at 60 MPH .....then by all means do what you have to do.....Anyways, good planning is the key to success, there is no charge for going 5 miles slower other than time of arrival to your destination. As they say, Time is Money!

 

Drop a gear. Is 10th overdrive? I going to guess that your best mileage comes at ~1400 -1500 rpm in direct.