My mom told me that when she bought her car new it got about 20 miles to the gallon (highway), but now 2-3 years later she says it gets 34 miles to the gallon. I'm just curious to see if it is true.. Created by Ash. cars-transportation-import - other-cars-transportation-import

Is it true that your car gets better mileage after you have used it for a year or so?

May 2021 7 3 Report

Is it true that your car gets better mileage after you have used it for a year or so?

My mom told me that when she bought her car new it got about 20 miles to the gallon (highway), but now 2-3 years later she says it gets 34 miles to the gallon. I'm just curious to see if it is true.

Cars & Transportation / Other - Cars & Transportation

hsueh010

Verified answer

Yes it is true that mileage can increase after a break in period, but what your mom saw is atypical. Typical results on fuel improvement is between 10%-15%

New engines need to be broken in, this allow the rings to seal/seat properly inside the cylinders.

Most modern day vehicles, recommend the engine be broken in by driving it "hard" to get the rings and cylinders to form a seal. Typically within a months time.

http://www.mototuneusa.com/break_in_secrets.htm

marcsweet_007

When you buy a new car all the mechanical parts are designed to fit and last the life of the car. The engine is tight and isn't really "broken in" when new.

There is more internal friction on the moving parts that create more heat in the engine and less efficiency. It stands to reason that after 10k miles or more as parts start to loosen up that your fuel economy will improve.

Use of synthetic oils reduce friction but delays the break in of the engine so you may want to wait to use synthetic oil until after you put 5 to 10 thousand miles on the car.

PMack

Your mom either got better or worse at math - or she stopped pulling the trailer.

Seriously - as the others said, it will get better, but not to the tune of 70%, my Accord which is two years probably improved 1-2 MPG highway from when it was new.