Gas tank top-off?

what’s the story with topping off the gas tank? In the state where I live, there is only full service, and if you pay cash, the attendant will top off the tank to make it to the next full dollar…i read this was bad. Is it true? If so, what to do?


Here’s a bit from the Tappet Brothers themselves:

In your case, I guess I’d just request that they not top off the tank. Surely they can give you change if it’s not an even dollar? Anyway, it’s not worth getting an extra $.75 in if it risks messing up your evap system.

Yes, bad to do because it often forces liquid gasoline into the vapor recovery system, which can damage it and set off the ‘check engine light’. When you buy gas, tell them stop filling at the first click. If you’re paying by credit card it doesn’t matter, anyway.

Having been a ‘gas jockey’ in the 70’s, I commonly would top off to make giving change easier. Not much done now…

Especially at today’s gas prices, moving up to round to the next dollar generally won’t end up being the same things as topping off the tank. But yes, it is bad to top off the tank as it will eventually mess up the evaporative emissions system. If you don’t want the attendant to do it, just ask him/her to not put anymore gas in after the pump automatically shuts off.

Agreed, with everyone. Topping off your tank can potentially damage the evaporative emissions recovery system.

I doubt there will be any disagreement, unless some uninformed person decides to say, “I’ve been doing it for years, and I don’t have any problems.” If that happens, you’ll see a good old fashioned pile-on.

@Yusaku…just mention to the attendant to pull the nozzle when it clicks off. Topping off the tank went the way of the dodo bird when modern vehicles started becoming equipped with emissions equipment. That was over 40 years ago.

The OP apparently lives in either Oregon or NJ, the only two states that ban self-service gas pumps. However, that does not mean that the OP needs to sit there passively while the gas attendant does as he wants.

I live in NJ, and I take charge of the gas pumping process–either directly or indirectly.
Most of the time, I do the entire process myself in order to prevent damage to the evaporative emissions system, to prevent gas spills on the rear fender, and to prevent scratches on the paint from lackadaisical gas attendants allowing the gas cap to bounce off of the fender. Not only have I NEVER been stopped from doing it myself, but almost all of the attendants thank me for doing it myself.

In the rare instances where I can’t do the fueling myself (instances where the attendant must first insert his card in order to activate the pump), I make sure that I am standing next to the pump when it clicks off. At that point, I simply say, “That enough…NO MORE!”, or “Bastante…NO MAS”. This yields the desired result.

All the OP has to do is to get out of the driver’s seat and stop passively allowing gas attendants to do as they wish. It is YOUR car, you are the paying customer, and YOU should be controlling what goes on with your car.

I go to the first click period. I watched a girl continue to click it about 5 or 6 times trying to get the last drop in. I bit my tongue but wondered why in the world she would do that.

I must confess, I top off pathologically and have yet to encounter any problems. I’ve never had an evap system problem with any of my vehicles that wasn’t related to critters chewing on the rubber lines.

I will say that when the pump clicks off on my 97 F-150, you can get a good 3 or 4 more gallons in. Filling up my old Bronco was a very similar experience. You just had to trickle the last few gallons in in order to completely fill up the tank. Both the F-150 and Bronco exhibited that behavior from the days I got them. My Mustang on the other hand is basically full when the pump clicks off. You can only get another .5-.8 gallons of fuel in before it backs up into the filler neck. So I just fill it up to the next even dollar amount just for the sake of easier bookkeeping. With gas at $3-$4 a gallon I don’t think anything is going to be damaged by adding another .1-.3 gallons of fuel.