Facts or opinions on topping off gas tank

So, were driving across country and getting around 16mpg. If I top off - meaning putting in an extra gallon or two after the pump initially automatically cuts off - what are the possible problems with doing so?

Picture of the rig

 

None , By the time you drive out of the gas station Its no longer Topped off LOL

 

Some vehicles used to have issues with gas being sucked into the vapor canister, part of the emissions system, but not sure if it's critical on a Taco. I always top mine up, and haven't had a problem in over 2 years. Besides, drive 2 miles, and the gas is out of the filler neck anyway...

 

Gotcha - if I put in extra I can get to 300 miles before we start having to look for gas stations. Thanks dudes.

 

why tot take a gas caddy Just in case bro

 

I've read on many other threads on here and elsewhere that topping off your tank is a good way to ruin your charcoal canister

 

It's a charcoal canister.

It's also about $300 for the part itself, for a dealer to repair its over a grand. Not worth an extra gallon or two for most.

 

And several have done it. Expensive fix.

 

When looking it up we also saw that about the charcoal canister but wasn't sure so I thought Id pose the question on here. We'll just fill up to when the pump shuts off to be safe

 

I don't fill mine up to the top of the neck, just to the point where it's an even amount on the price.

 

No harm.

But OP said he does 1-2 gallons, which isn't the same.

 

Very true.

 

*did

Only filled up like that once and then Remembered reading that might not be good.

 

I've been giving it a couple of extra clicks for 148,000 miles with no ill effect. I almost always do drive a good distance after leaving the station though. I think the issue could present itself if you topped off on a hot day, and then parked the truck. Gas does expand when hot, and it has to go someplace.

 

Couple clicks out here is less than half a gallon, maybe a quarter tops.

Again.. not 1-2 gallons.

 

I only top off a click or two, but good to know that it can cause problems if you put too much extra in! I always assumed it can't be good to fill it all the way up to the top of the neck (and never have), and have heard that gas expands/contracts as the outside temp changes.

 

been clicking for over 50 years, just be prudent with the extra clickage....

 

This

 

I don't top off.

First click I stop.

The problems it can cause, on 4Runners anyway, are expensive and hard to track down. There's more than just a charcoal canister and all the parts are expensive.

The issue does not manifest in a maybe replacement of a $300 part but involves a host of expensive issues....on 4Runners.....

W

 

Been there done that. $582 about 7 years ago to replace the canister. Wasn't even trying to put more gas in. some just spilled while I was taking the filler out. 2 gallon tank can be had for $30-50. Would rather do that then a few extra clicks anymore. I think the risks are low but after being burned for almost $600 I won't take the chance on it.