GreenHybrid - Hybrid Cars - View Single Post

lars-ss · #2 (**permalink**) 03-04-2005, 06:36 AM

You will get better at achieving higher MPG figures as you learn to use the gauges and get the feel for the vehicle. One week is WAY WAY too early to be overly concerned...

There are many helpful posts on this website that will aid your quest.

There are many reasons for cars not achieving max MPG in the colder months...

Car engines must warm up to a certain operating temp before they most efficiently use the fuel. Winter months and colder temps make that transition from cold start to most efficient take a little longer.

Also: new cars (and all the Escape Hybrids are "new" as of three months ago) have what is called a "break-in period" where the metal engine parts are still grinding against each other more rigidly, creating more friction, which also reduces efficiency. Over time, the "extra metal" shaves off and gets lubricated better (expecially if you use Synthetic Oil) and the friction is reduced, which affect MPG numbers.

Also: Hybrids use the "electric assist" much less before warmed up, and since the electric assist is key in MPG gains, the car must warm up before the use of the assist starts becoming most effective.

Also: Winter formula fuels used in most states hold less energy and this also hurts MPG.

Also: Generally speaking, colder weather in many areas means "rain, snow, or slush or ice" on the roads - these things add additional resistance which the tires must push out of the way to contact the road, so they hurt MPG in that way.

Also: Tire pressures also are lowered by the cold. Most people fail to properly inflate their tires all year, but ESPECIALLY in the winter when it is cold and you might have dirty tires and you just dont want to deal with spending time in the cold airing up a dirty tire. Low tire inflation can cause blowouts and adds quite a bit of rolling resistance.

Also: Additional idling uses fuel, and many people in cold climes are used to warming their car up in the morning. That is good practice to stay warm, but BAD for MPG numbers. While idling, your car is getting 0 miles to the gallon !!

Also: People who use the defroster in a Hybrid are many times using the A/C compressor to help reduce the humidity in the car and clear the fog. That is a MPG killer too.

See this science page for more explanation:

http://tinyurl.com/3s7lo