I apologize if this has been asked before, but the hamsters are tired and I can’t think of any search terms that are longer than 3 letters (gas cap isn’t cutting it).
So, to the question…is there a reason that automobile manufacturers haven’t standardized the placement of the gas cap? It occurred to me while getting gas today that traffic flow at the gas station would be so much easier if the gas cap was uniformly on the driver’s side or the passenger side…it wouldn’t matter which, as long as they picked one and stuck with it.
Some people in chat were positing that the gas cap was always on the driver’s side based on the prevailing country of manufacture (i.e. American cars had the gas cap on the left, Japanese cars had it on the right, etc.). This has not proven to be true, as far as I can tell, since my Toyota has the gas cap on the left and my Pontiac Grand Am had the gas cap on the right.
So…is there a method to the manufacturer’s madness? What is the deciding factor on gas cap placement?
Back when GM used to make real cars, that is, with full frames, rear-wheel-drive and V8s, they put the fuel filler neck behind a fold-down license plate.
Both of my '87 Cadillac Broughams have this setup, and it’s very convenient to be able to use whichever side of the gas pump is available. And the fuel filler is invisible; it makes the car look nicer. I wonder, though, if it could be a safety concern in a rear-end crash.
Also, I believe that some older Jaguars, such as the XJ-series, had two filler necks (both leading to one gas tank). You could simply use whichever filler neck was closer.
Maybe it’s the opposite of the manufacturing country’s driver side. My Toyota has the cap on the left, my Saturn had it on the right, and I believe my Volkswagen also had it on the right.
Having the caps on different sides eases traffic at gas stations with only one entrance and one exit. Instead of having to circle around, about half the cars will use the left side of the pumps and half will use the right side.
I dunno if thats exactly why the caps are on different sides, but it does make sense.
I gues it has a lot to do with the internal config of the vehicle. Sometimes it just might be too much trouble (money- and time-wise) to bother to try and design the filler cap to be on one particular side only.
This is a good theory, but it doesn’t seem to play out that way in practice, in my experience. There are a couple of “one-way” gas stations I go to on a regular basis, and the lines for the left-side-caps is ALWAYS longer than that for the right-side-caps. Of course mine is a left-side-cap.
I have seen where there are several cars in line waiting for the left-side-cap pumps, but nobody using the other ones. Very frustrating.
So my guess is that more cars have it on the left side than the right side.
Instead of fixing the cars, why not fix the gas pumps? I’ve seen a few with retractable hoses that are long enough to reach the far side of a car if you parked reasonably close.
My observations have been that most cars have the fuel tank (and thus the filler neck) on one side of the car, and the exhaust piping on the other.
On FWD cars, it may be a little easier to flip 'em around - the exhaust comes out the front of the engine (usually), so you can decide which way to bias it as it heads for the rear.
On RWD cars & trucks, I suspect it may not be that simple. My Mazda pickup, for example, has a 4-cylinder engine with the exhaust manifold on the right (passenger) side. It would be quite a chore to re-route the exhaust over to the driver’s side, so it makes sense that the catalytic converter, muffler, and ultimately the exhaust tip are all on the right side. I’m thinking that this was the primary reason that the fuel tank and filler neck are both on the left.
Yet another reason a small car is better than a big car. I can’t count the times I’ve stretched the hose accross the back of my car to put gas in the “wrong side”. Most of the time this was on purpose.
Take this FWIW since I can’t back it up with cites, but I seem to recall reading an article about automotive engineering that the fuel tank is one of the last components designed into a car. There is a careful orchestration of the car’s systems to get every part to fit just right. The shape and location of the fuel tank isn’t particularly important, so engineers shape it to fit whatever space is leftover. Sometimes that means the gas cap is on the right, sometimes on the left. Most of the cars I’ve driven in recent years now have an arrow to indicate on which side of the car the gas cap is located.
That was it, I believe. Nevertheless, I agree. Having the cap in the center of the rear end of the car was very nice in allowing you to pull up to either side of the pump. Under the plate put it inconveniently low, though. Trouble is, extending it any higher leads to placement problems with sedans and coupes, and is obviously impossible for station wagons and other rear-opening body styles. And the filler tube extension would probably mess up the cargo space in a sedan’s trunk.
One beater I had was a '65 Pontiac with that arrangement. If you filled the gas tank too full, it dripped gas on the ground if you parked it pointing uphill - there were some problems with the filler neck being that low.
I’ve seen a few that advertise this on their pumps - “long hoses, pull up to either side”. I ignore that because wrestling with the damn spring-loaded python to wrap it around the car is just as bad as the usual demented automotive minuet to get pulled up to the proper side of a pump.
An arrangement I’ve seen in a couple of newer stations that DOES make sense is to have the hose descending from a swiveling overhead boom that can be swung out to reach across. I’ve only seen this a couple of times, though. Probably an expensive system.
I’ve seen some vehicles change filler location in different model years even though the vehicle itself hadn’t received a major redesign. I think it was a pair of Suburbans a friend had, one from the late '70’s the other 2-3 years newer with fuel doors on opposite sides. I think they put it on whatever side they have the most parts for (Gee, we have 300,000 left hand fuel doors. We’d better put the fuel cap on next year’s model on the other side of the car).
Just wanted to point out: Consumer Reports and some car safety groups have lobbied for years to get caps standardized on the driver’s side. Since most “oops, I just scrapped against a pole/parked car/etc.” type accidents are on the passenger side, this actually makes sense. But there seems no hope of it actually occurring. Perhaps it will effect you next car purchase: “Gee, I’d love to buy your WhizBang GTQZ for 4k under list, but since it has the gas cap on the wrong side…”
Well ftg, that’s funny.Some time ago I have seen a TV show on cars. They tested and compared two cars (one German and one Japanese, I think it was a Golf against a Corolla). In order to find some negative points for the Japanese car they stated “tank cap on the unsafe left side” (which is contradicting Consumer Reports). There are two reasons I can think of why they would find the left side to be unsafe:
a) they wanted the German car to win the test drive (which in the end was the case) and had to find minuses for the Jap.
or
b) in case you run out of fuel and then have to refuel on the shoulder it certainly is safer on the passenger side of the car.
Actually, the older Jaguars with two filler necks went to two separate gas tanks (the driver selects one or the other tank with a valve) and when you went to fill up you’d have to fill BOTH of them! Not convenient at all.
Hmmm… this is related to what I do for a living. And you’re mostly right. But…
The shape and location are important aspects of the design. Look at the Crown Vic Police Interceptor lawsuits that are starting to surface. Perfectly safe fuel tank, but according to the press (and not my professional opinion!) maybe not the best position – in a rear end collision the tank is punctured by other components in the car (note this only applies to the Interceptor and not the mass-market models of the Crown Vic or the Grand Marquis).
When designing the rest of the car, space is reserved for the fuel tank, and the tanks are only prototyped. Not until vehicle engineering finalizes everything else can the “final” fuel tank be designed. But even then, prototyping still continues, because there will be placement issues, last-minute changes, and the need to study weldability, leak-fastness, and manufacturing processes.
Nowadays tanks can be made in virtually any shape. Plastic tanks are hydroformed or injection molded (I think), and can be any size and shape. Steel tanks are stamped from two panels to almost any shape, and modern seam welders can easily weld the seams in three dimensions (in contrast to the limitations of a two-dimensional seam).
So, yeah, fuel tanks are something that generally can be left to the last minute, even though there’s a LOT of engineering going on to make them.
@skogcat: Yes it was a left-hand-drive corolla. The way car are sold in Germany.
@Chronos: Consumer report wanted (acording to ftg) all tank caps to be installed on the driver’s side. The Corolla was like this (left-hand-drive and Tank cap on the left side). In a country where you drive on the left (like Japan) the tank cap would be on the passenger’s side. So the contradiction is that Consumer Reports wants the cap on the driver’s side, which is considered unsafe by the magazine I saw.