Do you get better gas mileage by driving faster or slower?

Question

Cars are often marked with Highway and City gas mileages and the city gas mileages are always lower. is that because the speed limit is slower or because of the stops?

Answer 1

Accelerating to 35 mph takes more gas than driving at 35 mph, because you're trying to build momentum. Also, city driving is rarely at ideal engine speeds, you're sometimes caught between gears, whereas at highway speeds, you're already in the highest gear.

Answer 2

You get better gas mileage if you drive slower (ugh). City mileage is affected by the amount of stops and time you wait at the stop. Leaving your running but not driving will lower your mileage, too. As an example: if you are waiting at a train crossing, cut the engine, but be able to start as soon as possible because if you don't you will hear a lot of horns beeping and see some extended middle fingers. Keeping a constant speed will help lower mileage. Also, if you have a lot of extra weight in your car (usually in the trunk) that will lower mileage.

Answer 3

Both. Frequent starting a stopping uses a lot of gasoline, but speed is a factor, too. MPGs increase up to about 60 mph then there is a sharp decline. One great way to increase the gas mileage of your vehicle is to keep it in the 55 - 60 mph range when you're on the freeway. I actually added a full day on to the amount of time I can get out of a tank of gas by setting the cruise at about 58 mph instead of flying about at my usual 65 - 70 mph. BTW, using cruise control actually improves your gas mileage, as well.

Answer 4

Your driving habits can affect your car's gas mileage. Keeping your car in good repair is the first step toward better gas mileage, but changing your driving habits can boost the savings power even more.



Sitting in traffic will decrease your gas mileage.



When you take off after a stoplight or stop sign, ease your foot onto the gas pedal and gradually accelerate. When you stamp your foot down on the accelerator, you use far more gas than if you slowly accelerate to your desired speed. Don't accelerate so slowly that horns start blaring behind you, but use modest pressure on the pedal and you should be all right.



Pay attention while you're driving and learn to anticipate a red light. Your gas mileage improves when you coast toward a stoplight than when you continue to give your car gas until the last minute. The same is true for stop signs and traffic ahead; take your foot off the gas and just coast in. You always burn less fuel when you coast than when you're giving your vehicle gas.



Rocketing down the interstate highway at eighty miles per hour might seem like fun, and you might reach your destination a little ahead of time, but the faster you go on the highway, the worse your gas mileage. Adjust your driving habits to the speed limit on the highway to improve gas mileage and resist the urge to crank your car to the maximum speed. The same is true for country roads where you might be inclined to speed a little bit.



Pay attention to the news before you leave your home and try to choose routes where traffic will be less heavy. When you sit in traffic, you burn unnecessary fuel, decreasing your gas mileage. If you see a roadblock ahead or hear about an accident on the radio, adjust your route accordingly. Most large cities (and even small towns) have multiple methods of reaching your destination, so keep a key map in your car for those occasions where it doesn't make sense to stay on your intended route.



Both using your air conditioning and driving with your windows down will decrease your gas mileage, so always choose one or the other. When you need to roll your windows down, always turn off your air -- and vice versa -- to control your gas mileage. Similarly, pay attention to the temperature in your car and only turn your air conditioning on to the optimum setting. There's no reason to blow cold air on its highest setting if you're already comfortable.

Answer 5

With city driving you are constantly stopping and idling. When you idle, you get 0 miles per gallon. That is why you get less mileage with city driving. However, if you are driving at a constant speed, you will get better mileage the slower you go. This is to some extent because your gearing also affects it. I'm thinking you would probably get better mileage in 4th gear because 4th is usually a 1:1 ratio.

Answer 6

Aggressive driving (speeding, rapid acceleration and braking) wastes gas. It can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town.



While each vehicle reaches its optimal fuel economy at a different speed (or range of speeds), gas mileage usually decreases rapidly at speeds above 60 mph.



As a rule of thumb, you can assume that each 5 mph you drive over 60 mph is like paying an additional $0.20 per gallon for gas.



I find that most cars reach optimal fuel economy at about 45 -50 mph. The reason city gas mileage is lower is because of the accelerating and decelerating. Click on the link below to see an example graph showing the relationship between speed and fuel economy.

Answer 7

The key to good mileage is smooth driving- not accelerating or braking too hard. It is all about being aware of what is around you, and not being jerky with either the throttle or brakes. For example rather than drive up to the stop line at a set of traffic lights, slow down and roll up gently- if you time it properly you won't have to stop, and you won't have the braking/accelerating effect that means too much petrol is forced into the cylinders and not all used effectively. Other ways include making sure your tyres are inflated properly, your shocks are set properly and that you do not have any unnecessary weight in your boot/ trunk. Also remove roof racks or roof boxes when not needed, keep your windows up and air conditioning off.

Answer 8

Engines were made to go at all times. The faster you go the faster your engine has to work so the faster you engine consumes gas. It's just like the conscept of the body, You need food (gas) to maintain a certain level of performance (driving). If you run fast (speeding), you use up more energy (gas). If you move at a moderate pace (drive slower) the less energy you burn (gas). Also, did you know that you should never warm up your car? Like i said before, a engine is made to go all the time so stops hurt the engine. Once you turn on a car you should pull off right away. Always pull off slowly though until the oil has a chance to work it's way through the engine. My 2cents

Answer 9

Because of the stop go involved in city driving. Driving slower will increase your gas mileage.

Answer 10

The speed at which a car gets its best fuel mileage varies by model but most cars generally are most efficient at around 60 mph. City gas mileage is typically worse mainly because the frequent stops mean having to accelerate frequently and accelerating requires more energy than maintaining a certain speed, but also because of the lower speeds.

Answer 11

The answer to your question is slower. The faster you drive the harder your engine works the more gas you use. The reason for the two categories is due to variance in traffic conditions.



Highway driving is normally at a continuous speed with less stops and starts allowing your car to work more efficiently.



City driving has more starts and stops making your car work harder

Answer 12

You get the best mileage on a 45mph road that has very few stop signs or lights. Your engine is running at a lower RPM than if you were on a freeway. If your engine isn't working as hard you get better mileage.

Answer 13

Not one nor the other. The optimal mileage is obtained when driving at "cruise" speed, usually somewhere between 2500 and 3500 Rpms (the closer to 2500, the better).



City mileage is usually lower, because of lower speed limit, and having to stop and accelerate a minute later. Highway mileage, on the other hand, usually is at a constant speed.

Answer 14

Driving the speed limit is supposed to help gas mileage.

Answer 15

gas depends on the r.p.m. of your engine. the more you have to stop the more u have to keep reving the engine to get going again. but on the same token the faster u go on the highway the more your car weighs becuz of aerodynamics. the more aero dynamic your car the more force is applied to it. highway gas mileage is better becuz car manufactures know all this. so they make it so the car's aerodynamics dont kick into about 75-80 mph. and on the highway u stay at a more constant r.p.m.. hope this made sense

Answer 16

It's because you stop and go constantly as opposed to being on the highway where you just go. If you use your cruise control you get even better mileage because it's a constant speed.

Answer 17

slower. i increased my mpg by 4-5 just by slowing down to 55 from 65. of course it pisses people off that are behind me but i dont care.i think they should reinstate the 55 on all highways in the country.

Answer 18

Hi



It's because of the stops, the car needs more fuel in order to accelerate again. On the highway the car goes without spending more gas than it needs.

Answer 19

It's because of starts and stops and idling in traffic and at stoplights.