Why don't cars have compasses?

Having recently moved to the UK, my husband and I have been doing a fair bit of travelling up and down the country. We have been using rental cars, so no SatNav system.

On many an occassion, we’ve become quite disoriented and not known our bearings. It seems to us this could be easily rectified with a compass somewhere on the dashboard, in order to help you match your position to the road map.

Is there any reason why cars don’t have compasses? I know these days they are replaced by SatNav, but that’s many many decades of cars that surely would have benefited from them!

Well, my car does have a compass. I drive a '99 Crown Victoria and I have a compass on my rear view mirror. A little digital N, NW, W, SW, S, etc.

So, some cars do have compasses.

Mine does, in the overhead console. (It also functions as a thermometer, odometer, econometer, distance-to-empty…)

My parents’ last two Chrysler minivans have had an overhead console instrument just as Johnny L.A. describes.

You could always buy them from outfits like JC Whitney. Simply not that useful for highway navigation, IMO. Your position and direction along a known road is more significant, and a compass heading is often misleading, or doesn’t impart any real useful information.

Why? It’s not like you can suddenly decide to take your Camry North by Northwest. You have to stay on the roads, which seriously limits the usefulness of a compass. On top of that, imagine all the Little Old Ladies as they toodle along at 55mph on the 101North. They glance at the compass, and it says they’re heading West. Oh, noes! Much panic among the bluehairs, and traffic comes to a complete stop. Thank you, no. Leave the compasses to sailors and hikers.

Most cars don’t have compasses because most people don’t feel they need them. I wouldn’t be surprised if there were no factory-installed car compasses in the 50’s and 60’s. It’s certainly a minority of models that do have them.

Aftermarket add-on compasses have long been available. They generally aren’t particularly satisfactory, and even the good ones require the hassle of calibrating them and wiring them for illumination at night*.

*Yeah, I know, some have internal batteries to activate a light - but then you have to push a button each time you want to read it, which is an aggravation, not to mention a significant distraction when you’re driving in the dark and don’t know where you’re going.

I don’t agree with the sentiment that they’re of little use. Anyone with half a brain can sort out the general direction of travel, even on roads that wind back and forth, and that can be of tremendous value in unfamiliar territory. Knowing that you’re more or less headed north, rather than east or south, can confirm that you’ve taken the correct road in the correct direction. Sometimes there’s a huge benefit to that.

Addendum - where “direction” is nominal like “80E”, or you think of it in such terms as “towards Sacremento”. The unspoken assertion here is that by far and away the most useful piece of “low tech” navigational apparatus is a good road map. Then, the information that the road sign says “East Bumfiddle 31 mi” and you are on county road X-27, tells you what you need to know.

Why does a car’s compass need to be calibrated? Unless you are in the far north where the Earth’s magnetic field behaves strangely, I can’t see why a computer would have difficulty figuring out which way is north.

There’s a lot of steel in cars, as well as magnetic fields generated by the electrical system. The errors cause by the magnetic fields of the steel and the electrical systems are called ‘deviation’. A good compass should have a couple of screws that adjust small magnets to negate deviation.

There’s no need to get hyperbolic. If I get lost I’d like to know which direction I’m going in. If I had a compass I might not have gotten lost in the first place.

My PT Cruiser has an overhead digital compass/thermometer.

Everything above plus the fact that compasses can have other sources of error through things like g-forces. Airplanes need compasses and always have them but the real compass is a secondary instrument. The primary instrument is a heading indicator that is gyroscopic and tends to be a very expensive precision instrument. Using the real compass as opposed to this device requires straight and level flight and knowledge about any errors that are inherent with its use. OTOH, Wal-Mart sells bubble compasses for cars for a few dollars and I have seen them on several vehicles as well.

No, they aren’t good for “highway navigation”, but they are excellent. JC Whitney generally sells junk, but you used to see a lot of old duffers with them in their car -Often the old duffers are on to something.

I bought a decent one at a duty free shop overseas and they are very handy when travelling back roads in remote areas and or unfamiliar territory. Where they really stand out is if I know I need to head West for example, because I will eventually hit a major N/S artery. It’s easy to get turned around. GPS, Google Maps has greatly lessened the need - but still a great backup, along with regular maps.

Just another “My car has one” post.

Subaru Forester, and yes, I’m glad it’s there

I had to get an aftermarket car clock for one of my first cars. It came with a compass.

And while the clock worked quite well, the compass was a total piece of crap. Pointing to west, while the car was heading east, that sort of thing. Since then I’ve tended to view car compasses as junk, and untrustworthy. A neat toy that is more trouble than it’s worth.

It may well be that I’m wrong in that view, though.

So does my truck.

A compass would be next to useless around Montreal… the highways here are about as far off from geographic direction as I’ve ever known!


Notice that highway 20, an east-west highway, goes geographically north/south for a good stretch. As does the 132, the 40, the 720… (all even numbered highways in Québec are theoretically east/west but around Montreal, they follow the direction of the island, and ignore the true compass directions. Heck, coming off the Jacques-Cartier bridge, you have to head north to take the 132 east, which actually runs in a southern direction…) The 30 almost doesn’t go east-west at all.

I suppose they could be useful in more rural areas, but it just isn’t worth it for manufacturers considering that most people live and drive in cities anyways.

My 2003 Altima has one on the mirror-- it was a $230 option. It is a nice feature to have, but not for that price…