chart of cost savings by increasing MPG

[1 FMF]

ever figure out how much you actually save by increasing your miles per gallon?
If it was from some additive, how far would you have to drive and how much gas would you have to buy to make up that difference?
Well, here you go.

It's more significant when you have lower fuel economy.
The different curves represent what the increase in mpg is. So, regardless of what your current mpg is, if you increased it by 0.25 mpg, then use blue curve. If you increase it 1.0 mpg use the white curve.
The X-axis is what your fuel economy is currently, so if my car gets 25 mpg and I wanted 0.25 mpg increase I would see a savings of 1%. So for 100 gallons of fuel used, at 25mpg = 2500 miles driven, you would save 1 gallon and only have used 99.
Which is to say for 100 gallons of gas at $2/gal, you saved $2 out of $200 of gas.
1000 gal of gas over 25000 miles you save $20.
The more efficient you car is to begin with, the less you save.

 

[mechtech]

Off the top of my head, I would have thought the relationships to be linear.

 

[surfstar]

nope, as you have a higher base MPG, the % increase becomes smaller and smaller. a 1 MPG increase on 10 MPG is 10%, on 20 MPG it is 5%, 40 MPG 2.5%...

 

[pitzel]

Hence why say, a 50mpg VW diesel or Prius, would see more of an impact on MPG from running the airconditioner, as opposed to an Excursion land yacht.

The new high MPG cars are also moving to things such as electrically driven power steering, which has the most dramatic MPG savings on the high MPG diesels, as opposed to the savings one would see on a larger car.

 

[Drew]

I lose about 2 mpg while using the AC on my VW TDI