Gas cap location

A caller on today’s show asked why the gas cap is on one side or another. Why aren’t caps centrally-located in the rear of the car? My '92 vette and '73 Mustang both have rear gas caps.

Mechanically it is easer to have it on one side or another. BTW have you noticed that the filler is almost aways on the side away form the exhaust?

OK, maybe with a true dual exhaust it has to be in the middle? What about more modern cars with dual exhaust?

There may be a safety reason as to why gas tanks do not fill from the rear. In the event of a rear end collision, the tank should be as far forward as possible. This can be carried to extremes, however. My 1950 Chevrolet pickup had the gas tank in the cab behind the seat and my 1961 Corvair had the gas tank in the front compartment right up against the firewall.

Of course, the tank could be located away from the rear end, just the filler neck is in the back. Wonder if the actual placement of the tank for a side vs. rear fill is that much different. Only so much room under there.

The consumer advocacy groups in the '70s largely ended the rear-filled tank (see ‘Pinto’). For years, designers put the tanks behind the rear axle where they’d be crushed in a rear-end collision. When pressured to improve the safety of the design, they moved the tanks in front of or on top of the rear axle. It was easier to reach these with a side-located filler neck. (Still, there was no standard on which side for American vehicles.)

2 thoughts on this:

  1. I was told that the “rule of thumb” is that the gas gauge is on the same side of the dash that the filler is on. I think this is true more often than not, but it is definitely not true on our 2008 Honda Odyssey.

  2. Seems to me there ought to be a random distribution of left and right filled cars, because some gas stations are oriented to take traffic in one direction only. If most cars had fillers on the left, the left side of the islands would be under utilized.

I hadn’t heard the ‘gas gauge location = filler location’ before, doubt it’s true. Most gauges have a little arrow pointing to side where the filler location.

No ‘gas filler’ czar out there telling companies where to put them, just comes down to each company and where they want it.

Every car I’ve driven had the gas pump symbol located on the side of the gauge indicating which vehicle side the filler is. The only exception is my wife’s Neon which has the symbol at the top, but an arrow indicates the cap side.
Having said that, I still find myself occasionally on the wrong side of the pump…

Tom and Ray: you mentioned vapor recovery systems on this week’s show. Since I’m the kind to spend too much time reading up on US laws while listening to NPR, I checked the current EPA rules, which say that they are planning to phase out the requirement for recovery at the pump “probably sometime after 2010”, due to the implementation of Onboard Refueling Vapor Recovery (ORVR) in 2000+ model-year cars (and 2001+ model year light trucks). Since eventually all vehicles will capture the vapors themselves, we might get a return to long hoses. Yea, I probably need to get out more.


Sorry guys but the german reason wasn’t accurate… German cars have the gas cap on the right side so you don’t ding your door when getting out to fill up. Germans care for their cars far too much to run out of gas. Now that I’m back in the States this irritates me every time I get out of my Miata to fill up… I’ve either got to park far away from the pump or very carefully exit so I don’t bang against those concrete filled metal poles the use to keep people from running over the pumps.

The German gas cap, like many other
continental European cars is on the right because for many
years (and still today in some small cities) the gas
pumps/the stations were on the curbside. It has nothing
to do with running out of gas. ?The American-drive-in
larger multi-lane stations were not possible for Europe
that had limited urban space. ?Thus they set up small
curbside pumps. About the size of the old U.S. Photomats.
Having lived in Italy and France I remember these smaller
stations. The full service mechanic stations were rare in Europe- that was why mechanics worked for themselves and not for gas pumping companies.
In fact, Q8 gas just redesigned a new prototype for the Italian stations.
The idea is just pull over to the right and park at the curb. ?Urban
space is changing in Europe. Today in France, the bulk
of gas is sold at the commercial centers that have
shopping malls and supermarkets. ?The major
supermarket chains all have big gas stations (and the best
priced gas) in their huge parking lots. Maybe in the future
Europe will be switching to the left. ?So, what the Germans
were doing was re-fueling at an official curbside station on the right.
They were not running out of gas.

I frequently travel alone (sometimes my car, sometimes a rental) and prefer the gas tank on the driver’s side for safety reasons. While pumping gas, I can have all except the
driver’s door locked. Then, if someone suspicious approaches, I can quickly get back in my car, lock the door, start the car and drive away. If the tank is on the passenger side, this would be much more difficult and time consuming.

What about the following possible explanation:

what if the the cars that are design by Japanese or UK designers put the filler on the right hand side (the drivers side) but if the designer is for US or mainland Europe.

Or it could be a random decision

re: why BMWs have gas tank fill on passenger side. GUYS your reason about running out of gas is funny, BUT not accurate. I believe you will find that most all European cars have gas fills on the passenger side because when the gasoline stations were first built in Europe they were built very close to the side of the road, and the filler machine was up against the building. Cars would pull off the road (like a ‘pit stop’) and an attendant would fill the gas without having to go onto the road way.

Once I saw the gas leaking out of my 69 Torino when owned by T. C. I knew he had to get rid of the locking gas cap that one of us had put on it. He would start off quickly in that 428 Cobra Jet and lose about a pint of fuel. You just don’t want to waste that stuff at fifty-seven cents a gallon. I don’t miss the hinged license plate either.

I do miss the nice high rear fuel door and cap on the 79 Firebird. That made things easy and many people didn’t even know it was there. I liked the American Vacation Wagon with the filler at the right front fender. Tearing the license plate off to try to find it was one funny movie joke. The song Holiday Road by Lindsey Buckingham was great too.