first click to fillup

Uh Oh, you're gonna hear about this one in the following posts

 

I'll be the first - - - - NO!

I had a Lexus RX previous to my new Prius. I sometimes had the habit of going way beyond the first and more clicks at fillup. And yes, sometimes with a faulty pump gas sprayed out a bit. Well, at 88,000 miles my Check Engine light came on. $550 later at the dealer - Evaporation canister needed replacement. The service manager said these typically last well over 100K and asked me questions about my fill-up practices. He said some of the overflow can easily backup into the vapor collection system and cause early failure of the canister. Lesson learned. So now I stop at the first click, and perhaps up to the next .10 to even the purchase. No more. Not sure if the Prius is sensitive as well. But the SM said most cars are.

And spillage - not good for your brand new paint job.

 

I have topped up all vehicles I've owned until the fuel is -at- the top of the filler neck (until the Prius GII with bladder). I have -never- had a problem with the carbon canister. It's designed to have liquid fuel in it. What do you think happens to fuel vapour when the outside temp drops? Some of it liquefies, of course. Usually, once you start the car and move it, you will find there is still vapour in the tank and the level drops down so you can't see it.

I don't recommend this practice, because when the fuel expands (and it will most of the time - except in winter) it can either flow out or pressurize the vapour recovery system. This is not good, as it can cause small hoses to pop off. I suspect this was the problem the above poster had, but the mechanics didn't think about that and replaced the carbon canister. In the process they would remove and reinstall most of the small hoses in the vapour recovery system, "fixing" the problem, but still blaming it on the canister.

 

I didn't take the service manager's explanation of the part failure blindly. I googled 'overfilling gas' in autos and saw many posts by folks that this could absolutely be a causal effect to early failure of the canister. Also had a couple friends very experienced in car service (not Toyota, but) and they agreed. It could have a cumulative effect. So, for me, better safe than sorry.

 

All I know is:
More gas = More weight
More weight = worse gas mileage
I usually don't fill my tank up past half.

 

Wow, in a Prius that would only be about 5 gallons at a time, and if you didn't go all the way to empy then you'd be stopping for 2 to 3 gallons.