Gas caps on cars - which side?

May 18, 2005 1:01 PM

Sitting in a car today as my friend was filling her tank, and my colleagues and I wondered aloud why there doesn't seem to be a standard for which side of the car has the gas cap on it. The car we were in had it on the right, as do both my cars, but the others in the car had cars with the caps on the left. What logic do car manufacturers use to determine from which side fuel is delivered? Some vehicles have the delivery point at the rear, and I believe I once saw a car with the gas cap near the front somewhere. Anyone know a rough ratio of left / right on North American cars? If there is a majority, is it an ergonomics thing? Just curious.
posted by galto to travel & transportation (45 comments total)

The only thing I can add is that I remember reading somewhere on Click & Clack's web site (maybe in the Puzzler section) that more than 95% of US cars have the gas cap opposite the muffler.
posted by ObscureReferenceMan at 1:10 PM on May 18, 2005

A well-designed car would have the gas cap on the opposite side from the driver for the simple and obvious reason that it's easier for the driver to get out when his door isn't right up against the pump. However, when a right-drive model is brought to the US, they have to change the side the driver sits on, but they are not going to bother moving the gas cap accordingly (too much expense to duplicate the parts). Thus, many import cars end up with the gas cap on the driver's side. To further confuse things, some domestic cars are trying to imitate imports and thus have the gas cap similarly located.
posted by kindall at 1:23 PM on May 18, 2005

I swear this was asked before, but my searches aren't turning up anything. If I recall, the only standard was that the gas cap is always on the opposite side of the car as the exhaust pipe, presumably for safety (standards?) reasons. Other than that, it's completely random. Most cars these days have a little gas arrow under the fuel gauge which points to the side with the cap.
posted by Popular Ethics at 1:35 PM on May 18, 2005

Obscure - that was indeed a puzzler not long ago. I imagine there is no rhyme or reason beyond opposing the tailpipe (presuming it's not dual exaust!) and the shortest run/cheapest method possible. If putting it on the opposite side would save $0.001 you can be sure it would be there.
posted by phearlez at 1:39 PM on May 18, 2005

PE, really? (arrow) I'll have to check that out. I just acquired my first ever car a couple months ago and I'm still often stumped as to remembering where the cap is (Nissan, driver's side). At least a couple of times I had to get back in and drive around the pump because I got it wrong.
posted by matildaben at 1:40 PM on May 18, 2005

A well-designed car would have the gas cap on the opposite side from the driver for the simple and obvious reason that it's easier for the driver to get out when his door isn't right up against the pump.

I couldn't disagree more. I think a well-designed car will have the gas cap on the same side as the driver, for the simple reason that its that much closer to me when I get out of the car to open it. As to the import/domestic disparity, my thoroughly Amercan Dodge Caravan has the gas cap on the left.

Also, it is indeed true that the gas cap tends to be on the opposite side of the car from the exhaust pipes so that there is less chance of the combustible fuel coming into contact with the hot-as-hell exhaust gasses and pipes, as in the case that fuel is spilled from nozzle, lands on the ground, and splashes onto the pipes.
posted by ChasFile at 1:42 PM on May 18, 2005

Your Caravan has the cap on the left because single sliding door models have the sliding door on the right. The mechanism to interlock the sliding door and gas door on the dual sliding door models is quite complicated.

The best place for the cap IMHO is under the license plate like on my '66 but it's really tough to meet emmisions with it located there so no one does anymore.
posted by Mitheral at 1:49 PM on May 18, 2005

matildaben, I drive a Nissan too and when I can't remember (I've lived in the US and New Zealand, and I get mixed up sometimes), I pop the gas cap cover as I'm pulling in to the pumps and I can see the little door-thingy open in the side mirror. That's assuming your car, like mine, has the little lever inside to pop the outside gas cover. :)

I've seen Jaguars with the gas cap right up in the middle of the back of the car, between the rear window and the trunk/boot. It seems pretty dumb because you have to reach so far to fill it, but I guess it's equally accessible from either side.
posted by tracicle at 1:56 PM on May 18, 2005

I had always figured the distribution would approach 50/50, the intent being to reduce lineups at gas stations. If everyone had their gas cap on the same side, the most popular entrace of a gas station would end up with uneven usage of the pumps, or with half the people having to reverse up to them.
posted by shepd at 2:05 PM on May 18, 2005

My theory has always been that auto makers try to achieve a 50/50 split so that gas stations on average have cars pulling up on both sides of the pumps. If all cars had gas caps on the same side, gas stations would have, on average, half as many pumps available if they have a 'prevailing direction of traffic'.
posted by clord at 2:09 PM on May 18, 2005

No real answer, but to further add to the seemingly randomness of it all, my last car had the gas cap on the right. My new car has it on the left. Both cars are the exact same make and model, with a few years difference in between.
posted by Ruki at 2:17 PM on May 18, 2005

There used to be a lot more variation then now, modern safety standards have eliminated many of the options. For example a '58 sweptside dodge pickup had the fenders from a 57 wagon. The filler did double duty as the left taillight on the wagons so that is where the gas cap in the pickup was. Caddy's in the mid fifties had the same set up.

Old Beetles of course had the tank under the front hood and they didn't even have external gas caps until '68. You had to lift the hood to fill your tank.

When Rangers were full size pickups you could order them with 3 gas tanks and so you ended up with fillers on both sides.
posted by Mitheral at 2:22 PM on May 18, 2005

Nissan left-hand fuel door/right-hand exhaust here.

Just FYI: there were several cars from the 50's, Cadillac and a Merc (I think) that had the fuel filler under the rear taillight, you flipped up the taillight and stuck the nozzle in, very slick.

Also lots of rear-engined super-cars have the fuel filler on the front just in front of the windsheild (some Porsches have one on each side, one for fuel and one for oil
posted by Cosine at 2:30 PM on May 18, 2005

My parents used to have an '85(ish) Chevy Nova with the gas cap under the license plate, which had a spring hinge to flip out of the way when it was time to fill up.

I always thought that it must be a bad idea to have that style if you were rear-ended... maybe so, because I've never seen a similar setup since.
posted by Silent Thomas at 2:31 PM on May 18, 2005

To contribute to the confusion, I can say i've heard that the auto manufacturers are moving towards putting the fuel filler on the rear opposite the driver's side for the reason that if you run out of gas, or if the car breaks down and you need to fill it on the side of the road, it will be the side opposite of where traffic is passing. How often one is in this situation, I can't really say. But thats what i heard the industry is moving towards.

(that also would explain why imports have it on the opposite side.)
posted by indiebass at 2:38 PM on May 18, 2005

tracicle, that's great! I do have that lever, although I haven't yet tried reaching it with the door closed. This place is such an education for an aging first-time driver.
posted by matildaben at 2:40 PM on May 18, 2005

Nissan NX/Pulsar: left side. And a dual-purpose lever that pops the cover one way, and pops the hatch the other. I never did get that 100% sorted out in the decade I owned the car!

Subaru Forester: right side. I hate that: I'd rather it on the right, so I could safely pull close to the pumps.
posted by five fresh fish at 2:43 PM on May 18, 2005

Right, left, same difference. Adjust notations above accordingly. Yes, I do have problems understanding directions.
posted by five fresh fish at 2:44 PM on May 18, 2005

Oh, I forgot to mention some old Firebird/Camero's with the fuel filler under the rear license plate with the tailpipe running right underneath it from one side of the car to the other.
posted by Cosine at 2:44 PM on May 18, 2005

My ’95 Nissan 200SX also has the two function trunk release one way / fuel door release the other lever, I think it’s very well thought out and efficient, yet I do occasionally mix it up too.

Slightly off-topic: The power window switches are also very well thought out, to my mind, a flat horizontal switch that you push down on to lower the window or hook your finger underneath and pull up to raise the window, yet EVERY person who gets in the passenger seat and tries to lower the window initially pulls UP on the lever! Any thoughts?
posted by Cosine at 2:50 PM on May 18, 2005

On the power window thing: Many cars have a toggle switch sticking up to activate the windows, pull it toward you for down and push away for up.
posted by Mitheral at 2:55 PM on May 18, 2005

I had always figured the distribution would approach 50/50, the intent being to reduce lineups at gas stations. If everyone had their gas cap on the same side, the most popular entrace of a gas station would end up with uneven usage of the pumps, or with half the people having to reverse up to them.

I disagree. All cars should have their gas caps on one side only - the driver's side, as God intended - so that everyone will pull into the lane from the same direction and face in the same direction.

My observation is that about 75% of cars get it right. The other 25% are designed by chuckleheads.
posted by yclipse at 2:57 PM on May 18, 2005

Not really answering the question but clarifying one thing the poster said about some cars having it in the front rather than in the back... I had a '68 Karmann Ghia that had the cap on the passenger side right up near the mirror, pretty close to where the glove box is. The actual tank was in the trunk (which in Ghias and Bugs is in the front not the back...) so I guess it was the closest place to keep the cap. I belive older Porches have there too.
posted by pwb503 at 3:18 PM on May 18, 2005

When I bought my 2004 Saturn Ion, the salesman told me the gas cap was on the right so I wouldn't get hit by traffic when filling the gas tank on the side of the road.

This struck me as utter nonsense. I've run out of gas and had to put gas in on the side of the road exactly once in 25 years of driving. It would be over-engineering to take into account an event that infrequent.

My Neon was the first car to have the little arrow on the gas gage that pointed to which side the cap was on. That is brilliant engineering. I don't care which side the cap is on, as long as there is a simple, visual clue on my gas gage.

I remember the under the plate caps. You wedged the cap to keep the plate from snapping back while you put the hose in.
posted by QIbHom at 3:19 PM on May 18, 2005

I don't care which side the cap is on, as long as there is a simple, visual clue on my gas ga[u]ge.
This is primarily for fleet vehicles, i.e. rental cars. Obviously, if it's your own car, you know where the gashole is.
posted by kindall at 3:25 PM on May 18, 2005

My old Toyota Pick-up (that was the actual model name) from '94 had the fill on the right; my '03 Tacoma (basically the same car) has it on the left. Personally, I prefer it on the non-driver side for the reason kindall mentioned earlier.
posted by LionIndex at 3:38 PM on May 18, 2005

In terms of power windows, by 2008 all cars in the US will be required to have the lever type switch (pull up to raise the window and push down to lower it): Which power-window switches are safer? at ConsumerReports. It's to keep young kids from accidently crushing theselves in the window (since other than the type you described, it's easy to accidently push down and keep pushing down the button to cause the window to go up).

As another data point, my Saturn's (98) gas cap is on the left and my Subaru's (97) is on the right. I can remember this when I switch cars because both of them have the gas cap on the same side as the fuel gauge (and no, I have no idea if either car planned it that way).
posted by skynxnex at 3:42 PM on May 18, 2005

Thanks for asking; I'd been wondering about this.
posted by Mars Saxman at 3:47 PM on May 18, 2005

Both my '94 Camry and my '89 Ranger (yeah, two cars, I'm livin' large--between the two of them there are about half a million miles on the odometers) have the exhaust on the passenger (i.e., right) side and the gas cap on the driver's side. A Dodge Durango I had occasion to drive not long ago had the same setup, with the addition of the arrow on the gas gauge.
posted by box at 3:47 PM on May 18, 2005

Most German cars have the gas on the right. This makes perfect sense in a small village where you fill up by pulling off to the side of the road and use the pump hanging on the wall on the narrow street.
posted by Nelson at 4:16 PM on May 18, 2005

It was under the plate in my '82 Bonneville and I loved, loved, loved that. Never had to worry about what side I pulled in on, could get gas everywhere. It felt like having that blood type (AB?) that was the universal recipient...
posted by GaelFC at 4:16 PM on May 18, 2005

Most cars will have the gas on the same side of the car as the gas gauge - so says my bf who worked car sales for years. Is this really the case?
posted by Coffeemate at 4:22 PM on May 18, 2005

I've found that the only real way to predict which side the gas cap is on when driving an unfamiliar car is to carefully study the tiny Gas Pump icon near the Fuel Gauge. The nozzle on the icon is the hint.
posted by ktrey at 5:00 PM on May 18, 2005

The reason the filler door is opposite the muffler in single-exhaust-only cars is that the fuel tank and muffler occupy the same space on opposite sides. Muffler position can vary depending on the easiest/cheapest way to route the exhaust around the engine and transmission components.
posted by notsnot at 5:22 PM on May 18, 2005

I remember thinking about this as a kid (yes, I was a weird child) and figuring out that American cars had the gas cap on one side and imports on the other.
posted by deborah at 5:47 PM on May 18, 2005

When I bought my 2004 Saturn Ion, the salesman told me the gas cap was on the right so I wouldn't get hit by traffic when filling the gas tank on the side of the road. This struck me as utter nonsense.

Strikes me as nonsense as well -- if you're on the side of the road and you have to get out to fill your gas tank, the safe thing to do is to pull as far off the road as possible. If you have to leave enough space on the right hand side of the road to get in to fill the gas tank, you're going to be at greater risk while you open your door and get out of the car just to start the process.

Oh, btw, all four cars in our household (Dodge Durango, Nissan Sentra, Saturn Ion, Porsche Cayenne) are left side tanks. I think. I've only had to get gas in the Durango and Sentra. The latter, btw, also has the dual gas tank/trunk release lever. Very nifty.
posted by Dreama at 5:51 PM on May 18, 2005

Sorry, but for me the best part of this entire thread so far is kindall's use of the word "gashole." Say it. Hee hee hee...
posted by attercoppe at 5:59 PM on May 18, 2005

Yeah, someone submit that to the OED for me, willya?
posted by kindall at 7:30 PM on May 18, 2005

The Chevy trucks and SUVs we've had are all left side fill. My 72 Buick Skylark has it under the rear license plate which is the coolest. It's much easier to overfill and slosh a bit on the ground that way because the nozzle isn't much higher than the tank.

Now my brother recently got a new Pontiac GTO which is actually an Australian car and it has the filler on the right. Different from any GM car I've ever driven.
posted by 6550 at 8:50 PM on May 18, 2005

notsnot: Aha. I figured it was an integration issue. The location is probably not a real high priority aspect of the vehicle design, so it gets left until other decisions (engine placement, exhuast routing) force the cap to one side or the other.
posted by Popular Ethics at 7:37 AM on May 19, 2005

Thanks everyone. Wow... lots of feedback on this one. I liked a lot of the responses. The one about the right side being safer to avoid traffic if you need to add gas at the side of the road.... we agreed that the situation would be so rare that it shouldn't affect the design considerations. I'll have to check into the whole gas cap on left = exhaust on right (and vice versa) theory.

Ultimately, I thought the idea of an even distribution to reduce big lineups at gas stations made sense to me.

ps kendall, I loved "gashole" too.
posted by galto at 7:43 AM on May 19, 2005

kindall- Obviously, if it's your own car, you know where the gashole is.

Not always. I don't put gas in Mr R's car often enough that I remember which side the gashole is on. I find the arrow really useful (especially since the car I usually drive has the gashole on the opposite side). (and I'll have to check the pump icons, but I don't think they've got the hose on opposite sides.)

And the gauge arrangement on the dash is the same, so that's not a good indicator. (FWIW, they're both Fords, 1997 and 2000.)
posted by jlkr at 5:40 PM on May 19, 2005

It's not an import-right side/domestic-left side situation. Camry has it on the left, Subaru Forester is on the right. And on the Subaru, the guage is on the other (left) side of the instrument panel.

Some gas stations seem to be under the impression that all cars fill on the left. they have signs that say, "Keep right and pull up to front pump." Thanks, but if my car fills on the right, I'll be going on the left side of the pump.
posted by Kirth Gerson at 7:29 PM on May 19, 2005

As far as unusual locations...

In the back, behind the license plate: My 1984 Olds Delta 88. Sweet car. Had a V8. Vroom.

In the front, under the hood: That would be a De Lorean. The trunk is in the front, and the engine and other werks are in the back. Never owned one. Not much for brushed steel.

Now I drive an Accord (my third one). Gas is on the driver's side, and that's the way I like it.
posted by SlyBevel at 3:11 PM on May 23, 2005

If you've ever driven in Europe you'll see why they are on the right... Some gas stations are nothing more than pumps on the side of the road... pull over, fill up and merge back onto the road. Ive used them in Spain and Germany. Strange the Cayenne is on the left tho... its German. I like it on the right because I don't swing the door into the concrete filled steel pipes that surround the pumps. My Land Rovers and BMW are on the right and, yes, I do forget and embarrassingly have to 'go around' every now and then.
posted by freeflytim at 6:33 PM on May 15, 2006