Fuel Economy Tip – Drive The Speed Limit

This tip is the first tip because it will keep you from losing your money not only to the gas pump, but to tickets and insurance as well.

According to Fuel Economy.Gov, for every additional 5 miles per hour (mph) you drive over 60 mph, you are spending an additional $.19 per gallon of gas. At today’s national average price for unleaded fuel, that would be the equivalent to adding over 6.5% to your gas bill.

Let’s look at it in regards to the amount of money you’re losing in a year by driving 5 mph over the speed limit:

If you fill up your 12 gallon tank once a week, that $.19 per gallon ends up costing you $118.56 per year!

Don’t tell me that $.19 per gallon doesn’t add up over time.

In addition to saving you money at the pump, driving the speed limit saves you money in additional ways:

  1. Reduces your chances for a speeding ticket (that shouldn’t come as a shock).
  2. Reduces your chances for getting into a serious accident.
  3. Because of reasons 1 and 2, you’re more likely to have lower insurance premiums.
  4. Reduces the wear and tear on your car, helping it last longer.

All of these things considered, speeding probably costs the average driver several hundred dollars each year.

Care to tell me again why you’re speeding?


  1. Anonymous says

    you’re not factoring in the oppotunity cost that is lost by not getting “there” in less time.

    hard to do, but you’re ignoring it altogether.

  2. The opportunity cost is more than likely negligible, unless you’re driving a long distance.

    If you’re just taking a short 10 mile trip, I don’t think speeding is really worth the 35 seconds you might save. Maybe you value your time differently though.

    If you were taking a 1,000 mile trip, where an extra hour or so (assuming you went from 60 to 65 mph).

    Regardless, I don’t think people save as much time by speeding as they think.

  3. You also have to take all of the items I mentioned into account when you’re speeding:

    1. Increased fuel consumption
    2. Increased chance for tickets
    3. Increased chance for accidents
    4. Increased insurance premiums
    5. More wear and tear on vehicle

    All of those things considered, I think the opportunity cost that is lost by taking slightly more time to get somewhere is very, very low.

  4. In a city, you won’t get there any faster by speeding: Traffic lights.

  5. I agree 100%. So why even bother?!?

  6. Anonymous says

    Why do you say it’s negligible? Are you just pissed that you’re wrong? If I’m taking a 10 mile trip, I’ll burn about a quarter of a gallon of gas. I value my leisure time at about $25/hour, so using all your numbers, but going 5mph faster, I pay 5 cents more for my quarter gallon, but make up 20 cents in oppurtunity cost. Ooops? Even in the worst case of saying you value your life at minimum wage, it just balances out.

    As for the rest…

    1. Increased fuel consumption
    – Offset by getting there quicker

    2. Increased chance for tickets
    – Depends, 5mph is usually challengable

    3. Increased chance for accidents
    – LOL, someone needs to read some DOT reports on this

    4. Increased insurance premiums
    – Only if 2 is true, because 3 is wrong

    5. More wear and tear on vehicle
    – How so? You’re getting there faster, so you’re using your car less. If anything, this is completely neglible.

  7. First, if I’m wrong, I have no problem admitting it, so you’re off base on that one.

    After looking at your scenario your numbers make sense, but you’re basing it on a vehicle that gets 40 mpg (10 miles per quarter gallon) which seems a bit high considering the the nataional average MPG for light-duty vehicles (cars and trucks under (8,500 pounds) is only 21 mpg according to the EPA.

    For this argument, we’ll round up to 25 mpg.

    At 25 mpg, you’re actually using .4 gallons of gas. So, if you were going 5 mph over the speed limit, it would cost you an extra $.09 per gallon, bringing you opportunity cost savings down.

    In regards to my other points:

    1. Gas used isn’t a product of time, it is a product of velocity and distance, so the time saved wouldn’t reduce the amount of gas you save – you’re still using more because you’re going faster.

    For example, let’s say at 60 mph you get 25 mpg, but at 65 mph you get 5% worse gas mileage, or 23.8 mpg.

    At 60 mph it takes you .4 gallons of gas to get 10 miles.

    At 65 mph it takes you .42 gallons to get 10 miles.

    Thus, you have consumed more gas even though you’ve gone the 10 miles in less time.

    2. You’re correct, I did ultimately end up looking up a 1992 DOT report that showed increased speeds did not increase the amount of accidents.

    3. If you want to nitpick about opportunity costs, then you have to factor in the time and money it takes to challenge a ticket.

    4. Is still valid even if number 2 is thrown out because number 3 is valid.

    5. Yes, there is more wear and tear on the vehicle the faster you travel. The engine has to work harder to produce the engergy for the vehicle to travel faster. Again, this isn’t necessarily a product of time.

  8. Anonymous says

    A couple months ago I drove to montreal and calculated my MPG at different highway speeds, Here was the post i made then:

    Last week I drove from my home in kitchener, ontario to beautiful montreal, quebec, approximately 600 km away (375 miles).

    During the trip I knew I would be filling up on gas a few times so I decided to calculate my MPG at different sustained highway speeds. On the way there I drove during the night (8pm->3am). Not much traffic and could afford to drive at higher speeds. On the way back I drove during the day, it was nice and sunny and I wasnt in any rush so for the purpose of the experiment I drove the speed limit (100kph/62mph). Below are the speed brackets of sustained highway speeds and their respective fuel economy rating.

    100kph / 62mph = 38 MPG
    130kph / 80mph = 30 MPG
    150kph / 94 mph = 26 MPG
    170kph / 105 mph = 24 MPG

    The highway is very hilly and it was quite windy. During the tests I sped up down hills and tried to ease off the gas uphills so that my target speed was maintained as i crested the top of the hill. I am confident that I will be able to reach 40MPG on flat roads during less windy driving conditions.

    Although driving the speed limit offered incredible MPG I doubt I will do that again. The driving was tedious, and at times felt unsafe when old ladies and transport trucks were passing me on the 2-lane highway.

    When travelling at higher speeds I did have to slow down for trucks swapping lanes and then accellerate again to reach my target speed. This will damper the MPG. Trucks travel in packs driving closely behind each other so that they reduce their drag and increase fuel economy, they take turns being the lead truck, but pass very slowly.. trucks drive at around 110kph and they will pass each other at 112, on a 2 lane highway this blocks off the lanes for a couple minutes as one slowly passes the other and I got stuck behind trucks more then a few times.

    Overall the driving was pretty uneventful.. and running the MPG readings was the only thing I had to cut through the boredom. Its funny what little games you come up with in your head when you have to drive for 6 hours straight.

  9. Should read… “1. Gas used isn’t a product of time, it is a product of velocity and distance, so the time saved wouldn’t INCREASE the amount of gas you save – you’re still using more because you’re going faster.”

  10. Thanks for the comment and data. How long were you able to drive at 105 mph?!?

  11. Hmmm,your blog is not exactly what I was looking for,but it looks realy interesting anyway.You may check my new Auto Parts blog if you like.Good luck with your blog.

  12. Thanks for the post. I’ll be sure to check out your blog. Just out of curiosity, what were you looking for from this blog?

  13. Anonymous says

    It dosn’t tell when the artical was writen what the base price for all the saveings was calculated at.

  14. Anonymous says

    Driving the speed limit might sound good, but it can be completely unrealistic depending on where you live. Every state enforces laws differently; I live in Minnesota, and I probably average 65 in most 55 mph zones. On the freeway, I usually go 10-15 over the limit, but even then I’ll still have people passing me. I’ve never been ticketed before; by MN standards, I am not a fast driver. Cops generally aren’t going to ticket you if you aren’t going more than 10 over the speed limit. In other states (such as Iowa, according to my professor) from Des Moines), however, they actually enforce the actual speed limit, and going the limit is considered acceptable. Here, I would have people a lot of angry cars lined up behind me if I were to go 55 in a 55.

  15. Scott the Student says

    Dear Anonymous:

    Trying to look at your argument from an unbiased perspective, I find it too hard to see the concrete evidence behind your argument. The fact alone that using more power= using more gas makes it hard for me, personally, to understand how going faster is a good economic fuel tip. Yes, it is true that there are optimal speeds for given cars; my truck, for example, runs best at 65 mph, receiving about 10 to 11 mpg. However, this driving of 65 mph is over a long period of time, say an hour. If I were to drive for the same amount of time, at a different speed, I may not reach as high mpg. Although, it would be very difficult to commute everywhere at 65 mph. Maybe in the great state of Minnesota, you are fortunate enough to have roads and highways that are traffic free. But you have to understand that others are not as fortunate. Furthermore, getting from 0-65 (again, stating that 65 is my optimal speed) alone burns a lot of gas. It would be very convenient if there was a button to press so that everyone could achieve their highest mpg, but this dream is unrealistic.

    In addition, in regards to Mr. Carr’s four points:
    1. Increased fuel consumption – this is obvious and further more not negligible, after all, this is an article entitled “Fuel Economic Tip” not “What Satisfies You Most.” We are implying that your marginal costs are exceeding your marginal benefits, and that you are willing to sacrifice time in the first place in order to maintain some income.

    2. Increased chance for tickets – Yes, it is possible to talk yourself out of receiving a ticket. But law is law, and mph over the speed limit is breaking the law, and if a cop really wants to give you a ticket, they can.

    3. Increased chance for accidents – I was surprised to see that increased speed does not have such an effect on accidents, however I know from a personal experience, that it’s a lot harder for me to slow down when I’m going 60 then when I’m going 30. I sure would not want to have anyone jump in front of my truck, but I won’t rely that people will stay out of the way, and therefore, if I don’t want to take a chance of getting sued, I’m perfectly fine with going a little bit slower.

    4. Increased insurance premiums – Insurance companies reward good drivers. Wasn’t it on one of those Allstate commercials? Yes, not all insurance companies are going to reward good drivers, but they will punish bad ones. What consists of bad drivers? How about wreck less drivers? What’s wreck less driving? How bout driving over the speed limit?

    5. More wear and tear on vehicle – You’re going faster… so you use your car less= no wear and tear? Surely I must be missing something in this argument, because frankly, I am finding zero sense in any of it. However, let me try to explain Mr. Carr’s argument. When you walk up a hill, you get pretty tired. You reach the hill, maybe a little bit winded, and maybe experiencing a faster heart beat. But that hill was pretty big, and took you a good 15 minutes to reach the top. Now if you were in a hurry (say supper was on the table…no one likes cold mash potatoes) you would decided to sprint up that very same hill. When you reached the top, you would be very tired, more tired than you would be from walking. You would be breathing a lot heavier, your heart would be racing a lot faster, and maybe even your feet hurt. However, sprinting up this hill, although it poops you out, is good for you. It builds endurance and is good for your blood pressure. But in order to receive more endurance and better health, you have to provide yourself more energy than you would from walking (i.e. more water, protein, and vitamins, and perhaps lavish foot massages). The same goes for your automobile. Stop and go traffic is not good for your car, this I will agree with, but that doesn’t mean that it’s not cheaper. Running your car at faster speeds requires more fuel and better care of everything that’s powering your car (engine, tires, drive train, etc.), they need their lavish massages too. All in all, using your car for a shorter amount of time does not by any means reduce wear and tear. Wear and tear is caused by how much work you demand from your vehicle, not by how much time.

    I thank both of you for grabbing my attention, I love hearing all sides of an issue, and love even more when I can display my knowledge and have people agree. Although you two seem to be getting a little out of hand with personal attacks, I enjoyed reading your arguments. I hope that I didn’t offend anyone with my argument. If I did, I am sorry. I had no intention whatsoever so insult anyone, and if by all means I am wrong, go ahead and tell me so I can stop believing false information. Thanks again, and happy holidays.

  16. I think it’s important to note that the legal speed limit was formulated without regards fuel economy (at least in most places). It would be more accurate to say that one should find their vehicles “sweet speed” at which fuel efficiency is maximized. On most passenger vehicles, that speed is around 60mph, but for many trucks and SUVs, it’s actually closer to 85 mph or so.

  17. I have a hard time believing trucks are very efficient at 85mph, did you mean to say 65mph? Is this due to their larger engines?

  18. I stand corrected, just read the 85mph thing…

  19. HERE HERE!!! Excellent arguement

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