Gas mileage vs Car's Mileage

[daemonite]

Do cars get worse gas mileage when they are new? I heard someone day that your car won't get it's optimal gas mileage until it's fully broken in at around 10,000 miles is this true? I didnt start monitoring my gasmileage until 5,000 miles...and from 5,000 till 10,000 miles...my gas mileage has been around 25 to 30mpg. Rising slightly from 5000 to 10000

 

[Palut]

It depends on the individual car, but I hear that gas mileage often does improve as break-in is completed.

 

[luvs2drive]

For every new car I've broken in, mileage improves with age. My best mileages usually come when the car has near 30,000mi on it.

 

[michaelc80]

My Subaru Outback Sport has been getting at or close to the EPA estimate since it was new. Most of the variations come from weather conditions or trailer towing. I now have nearly 12K on it and it's about the same as new.

 

[widman]

I just looked back at the mileage on a few of my vehicles. My 1995 4Runner gets about 11% better mileage at 300,000 than it did when new, but the jump was when I started using a diesel conditioner. It is somewhat distorted by my increasing the tire size twice, so it is really going about 8% further than the odometer reads. My 1999 4Runner is only about 10% better at 85,000 than when I bought it, but again the jump was with the diesel conditioner.

 

[Big O Dave]

Widman, you're running a diesel conditioner in the fuel? What one? I'm always up to a good experiment!