How much does MPG go down by for every person on the car?

Question

My 4 cylinder 1.8 liter Nissan Sentra has about 35mpg on the highway...that's with me alone in it. By how much do you think the MPG will go down for every person added?

Answer 1

The general rule is extra 100 pound = -1 mpg.

But I think that is just WAY TOO general.  You figure the heavier cars will be less affected.

Good Luck...

Answer 2

It shouldn't affect hwy mileage at all.  I had a Scion xB, which was light (2400lb) and made little power (103hp).  My two best tanks in the vehicle (38 and 36mpg) came on the hwy with four adults in my car + luggage.

If anything (maybe 2mpg), it would be city driving, because of the extra power it would take to stop and accelerate the vehicle.

Answer 3

You with the 'LOLLYPOP GUILD'?

Answer 4

Don't know if this holds true for the newer cars but in the 80's it was published that you loose 2% for every 50 pounds.  I suspect that it is only about 1% per 50 pounds now days with better technology.

Keep in mind that each 50 pounds results in less loss per 50 pound increment - math you know.