Attaining the EPA MPG

[Bruce Nunnally]

The second cycle is called the Highway Fuel Economy Test (HFET), also established in 1975. Unless you live in traffic-besotted L.A., it’s laughably slow by modern standards, with a maximum speed of 60 mph and an average of 48. But, back in the day, Congress had also mandated a 55-mph national limit, and the HFET reflected the intent, if not the reality, of American driving.

Keys to attaining the EPA highway mpg estimate for your vehicle: Max highway speed of 60 mph, average of 48 mph. Acceleration no faster than 3 mph/sec

Read More:

These Tests Failed You: Why Is the EPA So Bad at Estimating Hybrid Fuel Economy?

[Bruce Nunnally]

from fueleconomy.gov:

Highway: Represents a mixture of rural and Interstate highway driving with a warmed-up engine, typical of longer trips in free-flowing traffic.

So the EPA highway mpg looks like metro commuting?

EPA has improved its methods for estimating fuel economy, but your mileage will still vary.

EPA tests are designed to reflect "typical" driving conditions and driver behavior, but several factors can affect MPG significantly:

• How & Where You Drive
• Vehicle Condition & Maintenance
• Fuel Variations
• Vehicle Variations
• Engine Break-In

Therefore, the EPA ratings are a useful tool for comparing the fuel economies of different vehicles but may not accurately predict the average MPG you will get.

To find out what you can do to improve the fuel economy of your car, see Driving More Efficiently and Keeping Your Car in Shape.

[Texas Jim]

Interesting article...

If I drive slow enough on the open highway to be a traffic hazard... my car will get the EPA estimated mileage...(24mpg)... just barely.

But in real world highway driving, it gets about 20 to 21.5.

Get in a hurry and it goes downhill from there.

[Cadillac Jim]

I could run that test in low gear on my motorcycle.

My ETC got its best instantaneous gas mileage at about 75 mph. I haven't had a chance to look at the instantaneous figures on the CTS-V yet. I hadn't found the buttons when I got home from the drive from Texas. I got about 19.5 mpg for the trip, most of which was with the cruise control set on 80 mph to keep steady with traffic. Without the cruise control, my speed tended to creep down because I was new to the car. EPA highway is 18 mpg with automatic transmission. I beat city EPA, too, with about 15 mpg.