# Why haven't automobile manufacturers standardized gas cap placement? **URL:** \ **Category:** Factual Questions\ **Created:** [August 31, 2002, 2:50am UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401 "2002-08-31T02:50:55Z")\ **Posts on this page:** 12\ **Page:** 2
**Author:** ![racekarl](https://avatars.discourse-cdn.com/v4/letter/r/6bbea6/32.png) [@racekarl](https://boards.straightdope.com/u/racekarl)\ **Post date:** [September 3, 2002, 2:21pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/21 "2002-09-03T14:21:54Z")
It does appear that gas caps are standardized by manufacturers in other nations, just not in the US. The placement of the gas filler cap on the opposite side of the driver has nothing to do with filling it at the pump, but with filling it on the side of the road. By placing the filler cap away from traffic, you minimize the chance the driver could be hit by another car while filling the car from a jerry can on the side of the road. In addition, you are more likely to be hit by another car on the side of the car facing oncoming traffic. Hence, German and other EU cars have the fillers on the right side, and Japanese cars have it on the left. This of course is not universal, as US cars tend to adhere to the “where will it fit” method and have no consistent placement. ---
**Author:** ![amarinth](https://avatars.discourse-cdn.com/v4/letter/a/3be4f8/32.png) [@amarinth](https://boards.straightdope.com/u/amarinth)\ **Post date:** [September 3, 2002, 2:42pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/22 "2002-09-03T14:42:10Z")
> [@](#): > > \*Originally posted by Mr2001 \* > \*\*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’ve never seen a gas station with only one entrance and exit… are they common somewhere? And even if so, why aren’t people just backing in to the side that is convenient for them, if it’s open? ---
**Author:** ![Jdeforrest](https://avatars.discourse-cdn.com/v4/letter/j/49beb7/32.png) [@Jdeforrest](https://boards.straightdope.com/u/Jdeforrest)\ **Post date:** [September 3, 2002, 2:55pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/23 "2002-09-03T14:55:57Z")
> [@](#): > > \*Originally posted by Mr2001 \* > \*\*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. > \*\* Funny, my Saturn has it’s gas tank on the driver’s side. Maybe they even change the location within models. ---
**Author:** ![Anachronism](https://avatars.discourse-cdn.com/v4/letter/a/e56c9b/32.png) [@Anachronism](https://boards.straightdope.com/u/Anachronism)\ **Post date:** [September 3, 2002, 6:06pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/24 "2002-09-03T18:06:57Z")
Do people run out of gas often enough that safety while pouring in gas from a gas can is a concern? In close to 15 years of driving I have only run out of gas once and at that point in my life I was buying gas with loose change for a car that got less than 10 MPG :o ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [September 3, 2002, 7:16pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/25 "2002-09-03T19:16:51Z")
As an aside, if you’re driving an unfamiliar car and want to put in gas, most instrument panels I’ve seen tell you which side the cap is on, so you don’t have to strain to see the filler door in your mirrors. I drive rental cars pretty frequently, so this is handy. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 3, 2002, 11:34pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/26 "2002-09-03T23:34:56Z")
> [@](#): > > @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. I’m not following you. They wanted it to always be on the driver’s side. In the U.S., the driver’s side is the driver’s side. In Japan, the driver’s side is the driver’s side. On the planet Xgifefsg, the driver’s side is _still_ the driver’s side. ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [September 4, 2002, 3:16am UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/27 "2002-09-04T03:16:03Z")
Now that I think of it, I think the gas cap for my Saturn actually was on the left. There goes that theory. I’ve been keeping an eye out lately, and every car I’ve noticed has had the gas cap on the opposite side from the exhaust pipe, as **brad\_d** noted. Perhaps that also serves to keep the hot pipes away from the gas tank in case it ruptures? ---
**Author:** ![Nils](https://avatars.discourse-cdn.com/v4/letter/n/d6d6ee/32.png) [@Nils](https://boards.straightdope.com/u/Nils)\ **Post date:** [September 4, 2002, 10:24am UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/28 "2002-09-04T10:24:02Z")
> [@](#): > > \*Originally posted by Chronos \* > \*\*I’m not following you. They wanted it to always be on the driver’s side. In the U.S., the driver’s side is the driver’s side. In Japan, the driver’s side is the driver’s side. On the planet Xgifefsg, the driver’s side is _still_ the driver’s side. \*\* Yes, that’s certainly true. But according to the TV show the driver’s side is the unsafe side to put the tank cap. And after some more thinking about this, it starts to make sense to me. So the Corolla has the tank cap on the “unsafe” side and the Golf on “safe” side of the car. Of course this only aplies to Germany, USA, et al. In the UK, Japan, et al it is vice versa. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [September 4, 2002, 1:50pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/29 "2002-09-04T13:50:54Z")
> [@](#): > > \*Originally posted by Mr2001 \* > \*\*Now that I think of it, I think the gas cap for my Saturn actually was on the left. There goes that theory. > > I’ve been keeping an eye out lately, and every car I’ve noticed has had the gas cap on the opposite side from the exhaust pipe, as **brad\_d** noted. Perhaps that also serves to keep the hot pipes away from the gas tank in case it ruptures? \*\* Hmmm… my current car and previous car both had dual exhaust, so that eliminates that theory. I found this: > [@](#): > > DESIGN FUEL TANK FILLER NECK ON SAME SIDE AS OUT-GOING VEHICLE AND OTHER IN-PLANT VEHICLE LINES. > PARTS Fuel Tank, Sender, Tubes > DESCRIPTION Changing side for fuel fill neck may require relocation of existing fill equipment or new fill equipment and line rebalance. Results in T&F expenditures. Doesn’t explain the root cause of where the filler neck is, but does indicate why they stay where they are! ---
**Author:** ![sqweels](https://avatars.discourse-cdn.com/v4/letter/s/f19dbf/32.png) [@sqweels](https://boards.straightdope.com/u/sqweels)\ **Post date:** [September 4, 2002, 3:57pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/30 "2002-09-04T15:57:50Z")
FWIW, the older versions of the Mitsubishi Eclipse (my previous car) had the filler cap on the left side. The newer versions (my current car) have it on the right. Pisses me off. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 4, 2002, 9:37pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/31 "2002-09-04T21:37:16Z")
> [@](#): > > But according to the TV show the driver’s side is the unsafe side to put the tank cap. No, they said that the _left_ side is the unsafe side. For a car in Japan, that’s _not_ the driver’s side. ---
**Author:** ![Nils](https://avatars.discourse-cdn.com/v4/letter/n/d6d6ee/32.png) [@Nils](https://boards.straightdope.com/u/Nils)\ **Post date:** [September 5, 2002, 12:55pm UTC](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401/32 "2002-09-05T12:55:19Z")
> [@](#): > > \*Originally posted by Chronos \* > \*\*No, they said that the _left_ side is the unsafe side. For a car in Japan, that’s _not_ the driver’s side. \*\* Now I see our misunderstanding. It was a German TV show and they argued from a German point of view, where the left side is the driver’s side and therefore the unsafe side. If you take this car on holiday to the UK (or Japan) and run out of fuel you will of course be in a better position than a Golf driver. And by the way: My Girlfriend’s Smart (the tiny Swatch and Daimler-Chrysler car) has the gas cap on the right side (it’s a left-hand-drive version of course). But it seems to be possible to relocate the cap to the right side as there also is an opening which is closed in the moment. Probably they sell the car with the tank cap on the left side in country where you drive on the left (just a guess). [Previous page](https://boards.straightdope.com/t/why-havent-automobile-manufacturers-standardized-gas-cap-placement/126401.md?page=1)