Which car uses more gas: driving faster or driving a longer time?

Question

Car A and Car B are the same model (an SUV). Both cars must drive the same distance. Car A drives 100 miles per hour and takes 2 hours to get to the destination. Car B drives 75 miles per hour and takes about 2 1/2 hours to get to the same destination. Which car generally uses more gasoline? Or, is it the same amount? It's a matter of running the engine harder vs. running the engine for a longer time.

Answer 1

The car the is running faster will use more gas. The RPMs are higher requiring more gas to keep up the rate of speed.

Thanks!

Answer 2

Even if the car going slower takes longer to cover the same distance, it still uses less gas. Even though it spends more time on the road, it will get better gas mileage over the same distance. If the slower car got 25mpg over 100 miles and the faster car got 20mpg over 100 miles, the first car used 4 gallons of gas while the second car used 5 gallons. The amount of time spent driving doesn't factor in with Miles Per Gallon.

So, even if driving 100 miles takes longer to do, you'll use less gas by going slower. I hope this helps. Thanks.

Answer 3

Ofcourse driving faster will use more gas, so put it that way,
" It is out of your answer i think! " But you will get the idea,
If 2 cars, side to side set to a very long drag race or what ever it is! Both cars are filled just above the EMPTY SIGN! But have the same amount of gas!
1 drives Fast the other drives slow, now the fast one will beat the slow one on take off for sure, but temporally because he will eventually run out of gas because he is speeding! and the car will stop!
Then because the other driver is driving slow he will reach distance more than the fast driver because he is not accelerating, which means he is not using alot gas! :)

Answer 4

Car A will use more gas. When you drive OVER the suggested maximum speed which is typically set to 60 - 70 mph on American cars you start decreasing the MPG by quite a bit. For example in my car if I drive 70MPH on the highway I get between 28 - 29 MPG. If I drive an average speed of 75 I get 26.7. If I drive 80, 24.3.

Answer 5

I recently drove the 1500 miles from Austin to Pasadena CA in just 1.5 days. My Saab 9-3's mileage dramatically increased to 35 MPG driving for a longer time. I wasn't driving over the speed limit, but following my husband driving a 26' Penske. I am sure that even Consumer Reports would say "driving faster" after that horrible experience.

Answer 6

Assuming all conditions are equal like the same road, same traffic, same driver and same vehicle age, Car A will most likely consume more gas.

Running the engine harder means more gas is pumped into it rather than maintaining an average speed of 60-80.

Answer 7

Car A. Also, put it on cruise! The engine uses more gas with accelerating (passing) and slowing down (guy wont get out of the way) than an extra 10-20 mph.

Answer 8

The car driven faster uses more gas.
The increased wind resistance from higher speed will require the engine to work harder to push the car through the air. (Physics Class...The "co-efficient of drag" plays into your mileage formula)

Optimal gas mileage will be achieved when the transmission is in the highest gear, and the car is traveling at the lowest speed to maintain that gear (not down shifting)

At 70 mph my car gets 26-27 miles per gallon
At 46 mph, it gets 37-40 miles per gallon,
both speeds in 4th gear/overdrive
(It kicks into 4th gear at 45 mph)

Answer 9

Car A will use more gas. When driving the engine has to create energy to move along so the more energy needed to drive 100 mph will take more gas to produce the energy. Make sence?

Answer 10

I read somewhere this weekend that for every 5 miles over 60 you drive, it's as if you paid an extra 20 cents per gallon of gas!