driving the speed limit?

Question

or driving slower will that really conserve your gas?

trying to save money..hehe

Answer 1

Generally, the faster you go, the better mileage you get; but that's if you don't slow down and speed up a lot. You see, how much gas you use is directly related to how much you accelerate. So when you go a steady fast speed, you accelerate only slightly more than when you are going slowly, but get much farther. (better mileage)

It's better to go a steady slow pace than to speed up and slow down a lot, and if you do speed up, don't "step on it" - thats the faster way to get rid of gas ;)

Answer 2

Depends on the vehicle. Generally the rule of thumb is, accelerate gently and watch the tachometer, and when you reach your highest gear, look at the revs is at and stays at without shifting to the lower gear then the speed, and thats the ultimate point where your vehicle will have the best MPG.

Usually car manufacturer's know this on purpose, so for them to rate high in the EPA fuel estimate chart, they'll tailor their vehicles accordingly. GM purposely gives you a lower drive ratio, so your vehicle is revving decently at 55MPH, because it's what the government mandates. Problem is, the lower the axle ratio, the more you need to press down on the pedal, OR hope the computer compensates and shift down for you, for passing power. It makes for a busy transmission, but as long as it's smooth, you'll never notice it.

On my for example, the computer will tell me 26.2 MPG at 55, 23.1 at 70MPH, and 20.6 at 90MPH, and 19.1 at 105MPH. Or sometimes to increase it, I'll follow a huge 18-wheeler, and you'll see in the computer it'll start going up because I'm not cutting in the wide, rather, the truck is cutting it for me, helping me save fuel.

Now here's another example. I rented 2 very different cars, for the same route once. A Mazda6 4 cylinder, and a Mustang V6. Ironically, keeping both at cruise control of 95MPH, gave me 19.1MPG on the Mazda6, and 23.7 on the Mustang V6. Hmm so you would ask "WHY, if the Mustang has a larger engine?" Well, the 4 cylinder IS efficient at lower speeds...but the V6 has to work less harder then the 4-cylinder, to cut thru the wind at 95MPH. So these are the times when a larger engine is actually more efficient. The poor Mazda6' 4-cylinder was revving at 4400/4600+RPM to cut thru the wind at that high speed.

Hope this helps :)

Answer 3

Optimum fuel mileage is achieved at the speed when you go into top gear and the converter locks (with automatics). On MY car that is 46 MPH. That is too slow for the freeway, so I speed all the way up to 55 and stay in the slow lane with the trucks. (the 2 or 3 that observe the truck speed limit)

The only problem with running over there with the trucks is they are always kicking up rocks and bouncing them off my windshield, causing cracks. So, the money I save on gas goes to buy new windshields.

Answer 4

driving slower really wont save you any gas ,because your constantly having to get on the gas and off of it again,driving the speed limit usually is the best unless your out on the free way,once you get to a certain speed you can conserve a little gas buy holding a steady speed,and on good roads,good luck i hope this help,s.

Answer 5

I have heard that driving the speed limit will, in the long run, save gas and in turn save money. I have never really tried to prove if that's true or not.... I've got places to be and people to see and I'm always running late so I'd rather spend the extra buck.

Answer 6

The efficiency of a gasoline internal combustion engine is typically greatest at between three quarters and full load (throttle opening) and at around the same speed as the maximum torque. So accelerating as slowly as is common in the US does not save significant fuel, but running the engine above its torque peak does rapidly increase fuel consumption. It is generally most efficient to run the engine at about the lowest speed at which it can supply the desired power.

Answer 7

depends on your car...with mine, torque converter lock-up happens at 40 mph. so if i'm going 35, i'm using more gas than i am at 40. on the whole, going slower will slightly increase gas mileage, but to me it's not worth it.

Answer 8

higher speeds will usually lead to better km/L than lower speeds... so no, driving slower won't conserve petrol......

Answer 9

depends on your car.

Answer 10

above always