Better MPG

Better cooling = better MPG

Improving your cooling system will have a significant impact on fuel economy

In a new truck, typical on-highway fan run times hit a year round average of 5-7%. These run times significantly increase as your truck gets older. Over time bugs, dirt and debris get caught in the condenser, charge air cooler and radiator; restricting airflow and cooling efficiency. In addition, as a truck ages, the fins in the radiator start to deteriorate which will reduce the radiators ability to dissipate heat.


It takes between 10 - 70 horsepower to drive the cooling fan. This means if the fan is running longer, it can take a big bite out of the fuel economy.

Typical Heavy-Duty Fan Power Requirements:

  • 1100 RPM takes between 9-10 HP
  • 1300 RPM takes between 14-17 HP
  • 1500 RPM takes between 22-26 HP
  • 1700 RPM takes between 32-37 HP
  • 1900 RPM takes between 45-52 HP
  • 2100 RPM takes between 61-70 HP

At 1450 rpm, which is a typical cruise operation, a fan that is locked on can cause an 8-12% mpg penalty (assuming a 225 hp road load). With fuel prices at historical high levels, the cost of an upgraded cooling system from Detroit Radiator can be recovered in a matter of months.

Here is a typical scenario:
Take a 5-7 year old truck, running 150,000 miles a year. Statistically, the fan will be running 18% of the time - which equates to 27,000 miles a year. If we assume 7 MPG (without the fan running), the truck would use 3,857 gallons. At $4.00 per gallon, the annual fuel cost would be $15,428 (again, without the fan ever running). Since we know the fan will run 18% of the time, and we know that a running the fan can cause an additional 12% reduction in fuel efficiency, the truck would run at 6.16MPG - which equates to a total of 4,388 gallons used per year. At $4.00 per gallon for fuel, this is a total of $17,532 annually - which could be costing you $2,104 more than if the truck was running a new DRC cooling system.

Dan Elm from KY purchased from DRC a complete cooling system upgrade for his 379 Peterbilt. "I love the P5LPH Radiator with dimpled tubes and the PowerMax charge air cooler.  It's been over 100 degrees outside for the past two days and my fan has only turned on once! WOW! its a night and day difference thanks to Detroit Radiator."

Contact one of our knowledgeable sales staff and find out how to increase your MPG!

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