By on May 26, 2011

Editor’s Note: This piece, by John Carr, originally appeared at the National Motorists Association blog.

Wayne Crews recently posted an editorial on cost-benefit analysis and regulations. It’s worth a read.

In the 1970s the Carter administration prohibited speedometers from indicating speeds over 85 miles per hour. The idea was around before Carter, but his people implemented it.

Regulations require some justification. The justification was, people might not drive fast if they didn’t know how fast they were going. After some hand-waving and pulling numbers out of orifices it’s possible to fabricate a number of accidents and deaths per year prevented and call that the benefit of the regulation.

As part of Reagan’s regulatory reform the speedometer rule was scrapped. Rescinding a regulation requires some justification. The justification was that there was no real evidence that limiting indicated speed would reduce or had reduced driving speed.

An ineffective regulation is harmful because it imposes costs with no benefits.

Under the laws governing agency rulemaking, both Carter and Reagan were right. NHTSA, the agency responsible for car safety rules, does not have to prove its case beyond a reasonable doubt. It must show that there is some reason to believe a regulation would be good.

It was not impossible that the speedometer rule might have an effect, and it was also not impossible that it would not. When in doubt, do you regulate or leave the market alone? The greatest power of the presidency in domestic policy is the ability to tip the balance of bureaucratic decision-making.

Personally, I think the rule was silly. I don’t exceed 85 for the thrill of watching the needle land on 90. I don’t believe my car will explode or crash because I ran out of numbers. Anecdotal evidence suggests the limit was mostly an excuse for drivers to honestly tell cops they didn’t know how fast they were going.

An agency left to review itself will conclude it is doing a good job. In more recent years NHTSA has gone on to make up numbers on speed, alcohol, seat belts, and airbags.

To create an appearance of serious thought it pays for outside reports and quietly makes sure those reports justify the government agenda. The Parker report on speed limits was initially suppressed by NHTSA because it did not support low speed limits.

Where the costs and benefits are easily calculable and and comparable, it may be sufficient to have a separate agency audit the numbers.  When the costs or benefits are hard to determine, the decision is a political question and the agency’s role should be limited to making recommendations.

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53 Comments on “Don’t Drive Faster Than Your Speedometer Will Go...”

  • avatar

    My first car(1987 Taurus) had the silly 85MPH speedometer. I had that(2.5 HSC/3-Speed ATX) thing all the way down in the gear selector once whilst racing some Fox-Body Mustang.

    It was fun.

  • avatar

    The flip side of this is that now speedometers go so high that they are hard to read accurately. Is it Audi that uses a non-linear scale so that you can accurately read the normal speeds yet still have the high reading when you need it?

    • 0 avatar
      DC Bruce

      It’s Saab (at least on my ’02 9-5)

    • 0 avatar
      SVX pearlie

      My 1990s Subaru SVX had a 160 mph speedo dial. Easy to read within 1 or 2 mph. After I changed the rubber, I repeatedly timed it against measured mileposts as indicated accurate within 1 mph from 40 mph up to well over 100 mph.

      My current E60 has a similar dial, and is equally easy to read. It is, however, very optimistic…

      If you can’t read the dial, maybe the issue is with bad speedometer design.

      Or, most likely, it’s a PEBWAS issue.

    • 0 avatar

      Of course that’s regarding an Analog speedometer.

      How about Digital?

      I seem to remember digital speedometers that didn’t support 3 digits so you can’t tell how fast over 99 MPH you are going. I have vague memory’s of boat sized sedans back in the day with digital speedometers but the memory is too vague for me to google anything. Maybe it was GM, maybe it was Chrysler, either way it was a huge heavy gas gusseling 70s or 80s vehicle. You know back when curb feelers and phrases like “the door is ajar” were considered high tech. looks like a 2 digit speedometer.

      • 0 avatar
        Japanese Buick

        Heh, I rented a car with a digital speedo in the 85-mph speedo days. Naturally I had to do an experiment to see what would happen. The answer was that when the speedo hit 85, the numbers simply stopped increasing.

        Obligatory Panther Love: it was a Town Car

      • 0 avatar
        Brian P

        I am sure the third digit is there, but only has the lighting elements for being “1”. Canadian models (indicating in km/h) would have required that third digit (as “1”) for normal highway speed and I doubt if they would have made the Canadian and US clusters differently, other than a software setting.

    • 0 avatar

      My Audi A3 has a non-linear scale on the speedometer. I think I’d owned the car for a couple days before I’d even noticed; it’s quite natural. The size of the increments simply changes at 80km/h (50mph).

      • 0 avatar

        Your correct BP. I had a digi dash Grand Marquis and it was like this. It would go up to 199kph and then just stop. Interestingly the elements all faded rather quickly; however the “1”, due it its less-frequent use, managed to stay brighter. By the car’s end it was almost twice as bright as the other two digits whenever it came on. Always made it look weird.

    • 0 avatar

      That’s why I like my Mini’s speedo: goes to 180 on a linear scale, but it covers like 270 degrees and is as big as a dinner plate. Problem solved!

  • avatar
    Dr. Kenneth Noisewater

    I had a 77 Chevy Nova with an 85mph speedo, but no restraining piece so when my folks would ask how fast I was going on I-90 from Buffalo to Albany, I could truthfully say ‘I was going L.’

    • 0 avatar

      My 77 Chevelle has the 100mph speedo, with the right turn signal indicator at about 110, a ‘Fasten Seat Belts’ light at 120ish and the ‘Brake’ light at 140ish. It’s very optomistic past 85mph though when compared to GPS, though it will out run a Chevy Avalanche if you want a race of snails. I think I’ve gotten it to a gps verified 115 before it ran out of power.

      My Explorer has a speed govenor of 5200 rpm, so depending on how much grade there is, you could top it out at 95mph, or at 125mph. However good sense and general driver ease I tend to hardly ever push it past 75-80 on the highway.

      • 0 avatar

        Chevy Avalanche out of the box is speed governed to 96 or 98 MPH (can’t quite remember the exact number). I owned one and tuned the ECM to eliminate the governor. I got it up to 115 MPH and was about to crap myself out of fear I was gong to die at any second.

        115 MPH in a Porsche 944S2 is incredibly boring. 115 MPH in a 1989 Ford Probe is interesting. 115 MPH in a 2001 Chevy Avalanche is OH MY GOD I’M GOING TO DIE!!!

      • 0 avatar

        Chevy must design their vehicles to be freaking scary at high speed. I brought my Corsica up to an indicated 114 ONCE. I swear that thing was going to flip over backwards if I went any faster.

  • avatar

    …the best speedometers put the cruising speed around which you’ll spend most of your driving time straight up at twelve o’clock, say 80MPH for performance-oriented street cars and 60MPH for more pragmatic road cars, and nevermind track cars because you should really have your eyes on the road at the limit, gauging speed and revs by feel and sound…tachometers, likewise, should have the sweet spot of their powerband straight up as well, it’s just good ergonomics and easy readability…

    …i know i would have been a much safer driver in the eighties and nineties if i weren’t cruising with my speedometer pegged out somewhere in the unlabelled unknown, gauging triple-digit safety margins with nothing more than road feel, wind noise, and a generous helping of learn-by-experience intuition…

    • 0 avatar


    • 0 avatar
      SVX pearlie

      The best cars have 140+ mph speedometers, and cruise nicely to the right of top dead center.

    • 0 avatar

      I know the 1996 Ford Thunderbird was like that, and not just on the speedometer. All the gauges would basically point straight up if they were in the middle of their normal range. The tach would redline when pointing straight up. I loved that set up (although we didn’t buy the car for other reasons). I wish more cars were set up that way.

      I agree 100% with your post.

    • 0 avatar

      I too agree. This is one of the small things I love about my 328. The speed needle is perfectly vertical at 80 (actually 77, according to GPS), which makes 80 an aesthetically pleasing speed to cruise at. The tach needle is vertical at 4k, which is a good delineation between the boring and fun portions of the power band.

  • avatar
    A Caving Ape

    I wish it was just based on gearing. My 5 speed VW MK4 has a speedo that goes to 160, but unless I swap the transmission there ain’t no amount of boost that could get me there.

  • avatar
    healthy skeptic

    Hey, at least the limit was on the speedometer, not some limiter on the actual speed of the car.

  • avatar

    Remember the kph markings on the 85 mph speedometers that went to 140kph besides 85 mph? Some enterprising companies sold speedometer cable gear kits that made the needle accurate in miles per hour for the kph numbers, instantly converting your Big Brother speedometer into a 140 mph speedometer.

  • avatar

    The upshot of 85 MPH speedometers was legibility. I don’t need a 150 MPH speedo in my 110 horsepower Honda, but I would like legible 5 MPH increments so I can judge my speed more accurately (I also don’t need a tach with a slushbox, but that’s beside the point). I occasionally crack 85 MPH, even in my aforementioned gutless Honda, so something a little higher would be nice, the 110 MPH speedometer in my 4Runner was about perfect.

    Conversely, my Mustang reads up to 160, and that’s perfectly reasonable since the governor resides somewhere north of 140 MPH. Safe? Of course not, but if the car’s capable of that speed it’s for the best that the speedo can read at least that high.

    • 0 avatar

      Very true. A 140 or 160 mph speedometer is just wasted space in the gauge face.

      I don’t support mindless regulations supported with cherry-picked false facts, but as regulations go, the 85-mph speedometer was pretty low on the priority scale.

      And, face it: If you’re driving faster than 85, it doesn’t really MATTER how fast you’re going. You’re engaging in serious lawbreaking; if there’s traffic you’re putting yourself in real risk. It’s only pedestrian edification that you’d need to see HOW MUCH above 85 you’re going.

      Finally: In this age of GPS, a driver doesn’t really even need a speedometer. The GPS will give speed; and it will give ACCURATE speed – not speeds that are often as much as 8 mph over actual speeds (government regulations again, which do NOT allow a slow reading but are less concerned with fast readings).

      So, if I want to rocket down the prairie byway at 130 mph (I have done it, on a cycle) I don’t need to guess on how fast is “pretty damn fast.” Let the government bureau-weenies limit the speedos to 85; or 60; or 45. They’re idiots and they just keep on proving it.

  • avatar

    The irony is that a lot of the cars built back in that era could barely crack 85 mph anyway.

  • avatar

    Yeah, the 85 mph speedo was silly, but on the plus side, the cost of implementation was probably less than a buck per vehicle, with the exception of some low-volume imports. I’m not sure what’s the point in dredging this up 30 years later, except to point out that sometimes regulations are stupid. Color me shocked.

  • avatar

    The digi dash in my corvette went up to 85, but the digit part goes up to 255mph according to John Lingenfelter. At which point you rip the space-time continuum and it counts backwards.

  • avatar

    “Anecdotal evidence suggests the limit was mostly an excuse for drivers to honestly tell cops they didn’t know how fast they were going.”

    Back in the day, I got the “There’s no reason to be going 85” answer when the FHP caught me doing 103, but he did cut me a break and didn’t charge my stupid 19 year old self with reckless driving.

  • avatar

    My 85 forsa needle stopped at 140km/h. The car was unable to go faster…literally…the sound was so loud then (chopper kind of noise) that i din’t went that far too often…still miss that bugger!

  • avatar

    My 1989 Ford Probe had a digital speedometer setup. It would start to blink when you rolled over 85 MPH. BUT, if you went to the trip computer and switched to metric, the speed would would be shown in km/h until the computer shut you down at 185 kp/h. Never made any sense to me on why they could keep cranking with kp/h but not MPH.

    Those were the days…

  • avatar

    This 2nd fast and the furious quote took a while for me to catch…

    “and that Yenko will snap a speed-o cable in 8 seconds…”

    I finally realized they were talking about the 80mph speed-o

  • avatar

    The 85 MPH speedo limit pin on my motorcycle is a shift indicator for 3rd to 4th.

  • avatar

    In the late 1980’s I was a member of the Florida Highway Patrol Auxiliary. One night a trooper I was riding with clocked a Chevy Cavalier at 105 mph. This was one of the boxy, first-generation Cavaliers that wasn’t fast enough to get out of its own way. The driver must have had the gas peddle on the floor. Anyway, the trooper had a Special Service Mustang and it took no time at all to chase down and stop the Cavalier. When he asked the driver why she was going 105 mph in a 55 mph zone, the driver said, “I couldn’t have been going that fast. MY speedometer only goes to 85 mph.”

  • avatar

    I had a 64 Corvair as a kid. I tried to get it up to 100 one night on the LI Expressway. At about 80 I had to back down because the front wheels were starting to loft! The front of that car started acting a bit like a lifting body. (Don’t think it would have made it much past 80 engine-wise anyway.)

    One of my current cars has a 200mph speedo. It also has a switch that changes the needle to kph; then the car can only go 200 kph!

  • avatar

    Leaving aside the utter stupidity of doing 120 mph on public streets, it’s awesomely annoying to find 25 mph on a 140 mph speedo, especially in a car than could only go that fast if dropped down a mine shaft. Digital works fine, but is not as instinctive as a normal analog dial.

  • avatar

    Some cars with 85 mph speedometers didn’t have a pin at 85 to stop the needle from going higher. Owners of such cars were known to brag about making zero the hard way.

  • avatar

    Before the silly rule, most GM speedometers were legible, long and went to 120. Which covers every speed I have gone in my life. 115 is my tops (in a Honda Accord of all things).

    Since the rule was rescinded, it seems like the pendulum swung the other way and ridiculous numbers about. My 2011 V6 Mustang goes to 160 yet the car is limited to under 120 by the chip.

    I would like a non-linear speedometer as right now 99% of all my driving is in 15% of the speedometer face. I also liked the long horizontal speedometers as well. You could tell exactly how fast it was reading.

    I hate those old-lady rules like the 85mph

    • 0 avatar

      The fastest I ever drove was 116 in my ’64 Chevy SS convertible – on a two-lane road – at midnight, returning to base – one hand on the wheel, left elbow on the sill! Never did it again!

  • avatar
    Educator(of teachers)Dan

    “Don’t Drive Faster Than Your Speedometer Will Go”

    Damn it! There goes my plan to buy a mid 1980s Chrysler Fifth Ave and either de-smog the 318V8 or drop a new Hemi in it! I’d snap the speedo cable in 3 seconds.

  • avatar

    My 2011 Mustang GT has a 160 unit but only spreads about 180 degrees of the dial. It would be alot better if it covered about 270 thus making the numerals easier to read at speed. It’s governed to 155 anyway. 140 on the PA. turnpike seemed like 55 in my taurus. Only noisier.

  • avatar

    Wait, so I should or shouldn’t exceed the 160mph mark in my Honda Odyssey?

  • avatar

    I recall an 80’s thunderbird. The speedo was digital and stopped at 85 but kept going if you changed to kph.

    I drove a saab turbo at the time. I figured speed by the tach.

    Prior to that, I had a GLH turbo that had no peg at 85. The needle just kept going, with no numbers.

  • avatar

    Late 80s versions of milspec Hummers had a similar 85mph speedo. It was tough, but with proper planning and a good hill, you could go faster and peg the needle. Sometimes the needle would ‘break’, spin back to zero and cease to function.

    The post Gulf War 1 army had its moments.

  • avatar

    I remember when the Washington State Patrol was using bathtub Caprices with digital speedometers. The digits were big enough that if I was in the left lane with the stater beside me on the right I could read his speedometer reading.

  • avatar

    I am pretty sure that if you ever get caught speeding at 115mph in one of those cars, you could easily build a legal defense to make a claim that you can’t be fined for exceeding speed above 85mph.. since you thought that was the actual speed even though the speedometer actually works fine..

  • avatar

    Lamborghini had the cheap-arse solution to the expensive dilemma of having to tool two different sets of speedometers for the US and for the rest of the world.

    It would use the same speedometer but the numbers higher than 85 mph were covered in black paint and a stop bump inserted.

  • avatar
    Diesel Fuel Only

    My golf goes up to 160. Even the Euro versions are limited to 129 top speed to save the tyres – seems needlessly grandiose to me.

    It does have a graduated scale, I think it starts changing from 10 to 20 MPH increments at 90 or 100. I’d rather that they just made the numbers smaller and topped off the scale at 120, which is as fast as the car can go (unless you’re willing to change a few parts).

    No one believes that the car can go 160, it would be more impressive if it showed its actual top speed, 120 MPH.

    If you’d like to see a good-old-fashioned speedo without any peg go off-scale, this is one of my faves:

    He’s probably going downhill!

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