Does Cruise Control Save Fuel or Use More Fuel?

Don't forget that something like 73% of all statistics are made up.

 

I get better milage without cruise than with it.

 

The answer to that question depends entirely upon the driver. Some drivers will use less fuel by leaving the speed control in the 'off' position, while others will find that they get better economy by letting it set the speed.

Me, I use it more for convenience than fuel economy. I will typically turn it off during periods requiring frequent speed adjustment, and 'on' when I've reached a steady state such as flat, level highway with good traffic spacing, or climbing a long grade.

To summarize, the answer is: It all depends on how you drive with it 'off'.

 

I leave it on. Not for fuel economy(company driver), but because it is set at 62 off and 65 on. Get between 6.5-7 MPG. 2012 Cascadia

 

These trucks do get better mileage, but ours don't. Auto's, bad tires(Not the best for fuel efficiency), APU(catches wind), heavy trailer, and I have a rampbox under trailer that catches wind(ramp for back of trailer, I run dedicated).

Drove a 2012 manual at USXpress and it got between 8-8.5MPG. Same motor and truck, but was manual, no APUs and Michellin XDN2 tires. I'm surprised at the difference in the 2.

 

I notice on my truck that I get slightly better mileage on pedal than cruise according to the dash metrics. The way our trucks are set up , cruise is maxed at 61 , around 1150-1200 RPM in 10th. Small hills bogs down the motor because the rpm's are too low imo. Max pedal is 64 does better on hills that way, with weight or light at about 1400 rpm.

Still in mid 7 to high 7 mpg either way.

2010 Century Class Freightliner w/ DD15 and an Eaton 10.

 

I get better on the cruise. Set my truck at 57-58mph just at about 1200 rpm's, 100over peak trq is where I get the best mpg and my truck isn't in boost much at all. Doesn't spool over 24psi at this speed either. Anything over 59 I'm 10+psi all the time.

 

Many trucks especially lower HP rated motors will let the cruise control have more ponies than the driver....