Gas-Saving Moment of the Day: 55 MPH Speed Limits


You're not going to like this one. Here at KickingTires, we know we don't.

Cars are most efficient when driven at a low speed in their top gear. Therefore, changing speed limits on highways to 55 mph would save fuel and emissions, as well as reduce traffic deaths. For every 5 mph over the speed limit you drive, you lose 20 cents per gallon, according to the Department of Energy.

During the oil embargo in the '70s, the federal government tried the 55 mph national speed limit, and organizations like are eager to return to that standard. However, cars and trucks have come a long way since the era of disco. These days, driving 55 mph on the highway feels like puttering around on a tricycle. Today's vehicles are quieter and faster. When’s the last time you found yourself satisfied going 55 mph on an open freeway? In other words, a 55-mph speed limit may be as lost a cause as asking drivers to trade in their cars for a horse and buggy.

What do you think about reduced speed limits? Would you be able to scale back your highway speed for the cause of saving fuel?

With Gas Prices Rising and the Planet Warming, Is It Time to Drive 55 Again? (Autopia)

More Gas-Saving Moments of the Day (KickingTires)

By Stephen Markley | May 27, 2008 | Comments (29)



I wish I could, but I would get creamed by someone doing 90mph+.

I find a 55 mph speed limit pointless in LA with the traffic. People are sucking down a lot more gas in stop and go traffic than driving 75 mph when the roads are clear.

Also I have an 88 Mustang with 2.73 gears that I have driven cross country 4 times and my mileage was pretty much the same driving 70 mph or 80 mph. Ranged from 27-29 mpg. My best was 29.6 mpg cruise set on 80 mph from Salt Lake City to Las Vegas.

With a 70mph speed limit I try to drive 60 or no more than 65. I save about 2-3 mpg per 5mph decrease. It's worth the savings but you do get a lot of dirty looks from people. Taking the extra 5 minutes to get somewhere is worth it.


It looks like now I really have to get me one of these stickers:


Agree, I can live within speed limits. First mile over speed limit should be fined at$150.00 plus regular fine.
In addition let's raise the price of grain to match grude prices.


I drove 800 miles on vacation this weekend, and I set the cruise at 55-60 nearly the whole time. The best part about that is, you can kick back and let all those packs of ten cars all bunched up together pass you at 70+ every ten minutes. You don't have to hit the brakes, pass other cars, etc. Much less aggravation, plus the tach stayed around 2500 rpm the whole time, so that by the time I got to my destination and refilled the tank, I had clocked 32 mpg, beating my Mazda3's 2008 epa estimate of 29 mpg by 10%, or $10 total. $10 isn't much, but it makes up for the overpriced McDonalds garbage I had to buy at the only rest stop!


How about drive less, or get a better vehicle.

Let the suburbans sit in the right lane driving 50mph.
A modern car will get better mileage at 75mph than that suburban driving 50mph.

Lets see, in the '70s 3 speed automatics were common, now 6 speed automatics are common place.
The only speed limits for the open interstate highway are 100mph daytime, 80mph nighttime.


Why would anyone really be concerned about what somebody else's gas mileage is on the road? I don't care about it because people by different cars for different reasons. Also, I thought speed limits were originally set per the design specs of the highway/road. Not for the public's gas mileage. If the gas mileage on your car is your biggest priority, trade it in on a tiny hybird or 4-banger. If not, just keep quiet and enjoy it for the other reasons you bought it.


What about going back to gas rationing cards to conserve fuel? This method was used before I was born, so I don't know how efficient it was, but if we need to get people to drive less and drive economical cars gas cards may be the best solution.


So we'll all be languishing at 55 mph while the 16 wheeler tractor-trailers continue to scream behind and dangerously past us, 3 abreast at 90 mph?
If anyone is serious about safety - these are the guys that need to be restricted to 55 mph, not the average motorist. 80 mph in a modern car is not excessive, and remember that a slow, drawn out trip at a low speed is likely to cause even more accidents through fatigue and impatience, than a faster more efficient speed.
Its not always that "speed kills". There are a lot more factors than that.
Ultimately far more gas is consumed in crawling traffic gridlocks that could be relatively easily resolved through more intelligent timing and placing of traffic lights, better construction of intersections and smarter school zoning.
Town planners have employed the stupidist of the stupid for far too long and it is time that traffic is treated more like computer data - how to move the highest number of packets through the thinnest pipe. The answer is, keep it MOVING and keep it moving FAST.

Why do people suggest that you just get a new car to save gas? Not everyone drives a suburban or can really cut back on driving. I have a hyundai elantra that normally gets 30mpg on the highway. When I set the cruise a lower speed, say 55 or 60 I get on average about 33mpg. I think the purpose of the article is how YOU can save money on gas. There really isn't a need to get upset about what they drive or what YOU THINK they should do.

Why would anyone really be concerned about what somebody else's gas mileage is on the road?

Because their horrible gas mileage drives up demand which drives up the price *I* pay at the pump.


If people really do not know it saves fuel by going slower, then those limits are needed.
However only if people are willing to get up a little longer so that they don't have to drive so fast.


want to save fuel?
drive the speed limit(what ever it is)
close ALL drive-up windows(zero mpg)
what will price of fuel be?
In the 70's, the chairman of standard oil was asked(on a tv talk show in chicago)"will the price go to $2/gal?" His response was "if the news media convince the public that it will, we will raise it"

Want to save fuel - eliminate all Nascar and other forms of auto racing! This should piss some rednecks off. Here's another one- drill for oil on all golf courses - what a waste of land!. That should piss off the non-rednecks.


It does not get any worse than this suggestion to save fuel.

If people want to speed they pay more to drive. Everyone knows this. They are clearly willing to pay the price.

Think about how many minutes are lost going 55 mph instead of 70 mph?

The solution to all these problems is painful, but very obvious.

How to you make people drive less?
How to you make people make more rational car choices?
How do you make people drive slower (and accelerate less away from stop lights)?

Raise the cost of driving of course. And how do you do that?

You raise the gas tax significantly. This achieves all the goals without any distorsions. Does it work? Sure, just look at Europe.

The problem is all the politicans in this country are too timid (and too populist) to explain this to voters. Instead they try to sell half-ass solutions such as this and CAFE.

A gas-tax is unfair to the poor? Sure, but you could simply distribute the extra taxes back to voters as tax credits for poor drivers or use them for increased highway spending.


Newsflash for people calling for low speed limits to save gasoline - They don't work.

When 55 mph was the law of the land, gas savings were virtually nil. That is because of the fact that only 25 percent of miles traveled are on roads affected by the 55 mph speed limit.

55 mph didn't work. Case closed.


Newsflash for people calling for low speed limits to save gasoline - They don't work.

When 55 mph was the law of the land, gas savings were virtually nil. That is because of the fact that only 25 percent of miles traveled are on roads affected by the 55 mph speed limit.

55 mph didn't work. Case closed.

Troy S.

Slowing down requires effort. People can't even apply enough effort to use thier turn signal thus, lowering the limit will only apply to those who apply effort to follow the law. A small percentage of drivers.


Well, I saw a story on the news about slowing down - hypermiling. Of course they used a Prius in the demonstration but I decided to try it in my minivan. I can get 30 mpg in my van by always doing to posted speed limit and taking off slowly from stops. It's actually a more relaxing drive because I set the cruise control and everyone else just passes me but I don't have to fool with them. I've noticed other people driving a little slower as well. Most of the fastest drivers I encounter are guys in work trucks who aren't paying for the gas out of their pockets or snobs in expensive sports sedans who can afford the gas. I stay to the right and if I need to move over to the left to pass I do and the a$$ behind me who thinks I'm going too slow is just gonna have to suck it up for a few seconds until I finish my pass and move over. They don't care about my gas mileage, I don't care about their schedule.


I think, speed limit can be enforced really fast. Speeding cameras on overpasses, like in Europe. You speed - get ticket in the mail. Seriously. It can be even dangerous to drive slower then 10mph above speed limit. They tailgate, switchin lanes right and left, passing on the incoming lanes. Amazing!


here in Boston, you catch every single freaking red light on most major streets going to and from work. how about using some post-1800's technology to improve traffic flow? If what Henry said applies to most cities, then it should make a much bigger difference improving local street traffic.


No one wants to consider that the growth of speed bumps, circles, stop signs and other traffic calming devices (um, speed bumps do not make me calm) further reduces city fuel economy.

There are more fuel efficient ways to reduce traffic speeds - studies show drivers drive at a speed they sense is reasonable, largely regardless of speed limits, so altering urban planning to look for ways to reduce congestion and increase road efficiency should be on the drawing board, but as others have mentioned, road planning in the US is still in the dark ages.

Small, slippery, lightweight vehicles make the most sense for increasing individual fuel efficiency, and public transit, carpooling, HOV lanes, and telecommuting, among others increase overall efficiency. Where is the 21st century thinking? At least my 1980s technology motorcycle gets 50+ mpg



Welcome to the game.

Did you feel safer when driving slower and less aggressive?
Just laugh at those fools who will do anything just to be 1 second faster than you and while you are going easy on your bank account.


Seems a lot of people dont want to drive 55 again. I hope you like your empty wallets because that is just what you deserve. Driving 55 again would reduce our consumption rate by about 20%. This would cause fuel inventories to overflow and prices would fall quickly. But the it seem that the gas guzling fast driving crowd will not change their ways and the man we've got for a leader will let his big oil pals rake in the money from the dimwits. Y'all get what y'all deserve....suckers.

Jim Davidson

"Cars are most efficient when driven at a low speed in their top gear." That statement is false. Cars have an optimum cruising speed in top gear, below which they will get -lower- gas mileage. I see this all the time when watching the instant fuel mileage readout in my car.

I've been meaning to see where that peak number is, but I've haven't found a stretch of road or the time to do it. I would be willing to bet that in some cars, it is over 55 mph.

Jim Davidson

"Driving 55 again would reduce our consumption rate by about 20%."

Where in the world are you getting your "facts". First of all, a 55mph speed limit would only reduce consumption on open highways, where only a SMALL percentage of overall driving miles are accumulated. Secondly, 20%? Not in my car. I get ~24mpg at 70mph. At 55, I get ~25mpg. That's only 4%. Whoopdeedoo. Then you can factor in loss of productivity and increased delivery rates for all the additional time it is going to take to get anywhere.

This whole premise is beyond stupid.


It's basic physics that driving faster increases drag from the air significantly and forces your engine to work harder, so it will reduce your gas mileage. In California, just enforcing existing speed limits would make a significant difference, and probably save a few lives to boot. Given the severity of the current gas price crisis, slowing down a little doesn't seem like too much to ask. (I've dropped ~5 MPH and could go slower if necessary.)

Hey Henry

HENRY is absolutely wrong. the 55 MPH speed limit DID save gas nationally. Truck usage increased dramatically 1973-1980. Passenger car miles drive dropped. Trucks drive more on high-speed roads than cars. Sorry but you're dead wrong.

Look at the chart more closely next time

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