Last night when I left work I filled up the tank. For the first time I decided to top it off completely with the hope that I might continue that practice to reduce error in my mpg calculations. Of course it doesn't make sense to do that unless you're going to burn off the filler tube before parking it overnight, so I did it before my 80 mile trip home.

I was surprised by how much I put in after the first click. It was about a gallon and a half until I saw the fluid settle near the top of the tube. Then after returning the hose to the pump an coming back to replace the cap, the fluid was gone - it settled again meaning it could have taken more. How much I'm not sure, but that was a lot more than I expected.

So... now that I have driven home and back to work again, I have 162 miles on the tank and the fuel gauge still registers completely full. I did get kick-*** mileage on this tank (53.3 so far) but gee whiz, that's a lot of miles on a still-full tank.

Anyway, I was just hoping for a little discussion on topping off versus stopping at first click and so on. Wondering what you all do and why. Thanks.

Oh yeah, one more comment... I refilled 160 miles ago and the fuel guage still says completely full. Wow that's a lot of miles on just the top off. Yikes.

 

I always stop at the first click in all my vehicles - I fear that topping off the tank will flood the evaporative control system, mainly the charcoal canister, causing a problem.

Maybe it won't, as some will argue, but I'm not willing to chance it.

I'm happy with a 650-750 mile range per tank of gas in the Insight.

Regards,

 

If you saw the gas level go down like that you were almost certainly filling the vapor recovery canister. This can damage you car, void the warranty, and leads to excessive hydrocarbon emissions. We have clean cars, please don't pollute just to get a few more miles out of each tank.

Filling to the first click does produce a small amount of variability on a tank-per-tank basis, but that variability is eliminated when you do a lifetime mileage calculation.

~Droid

 

Top-off vs. first click is a controvesial topic. And has been discussed in other threads.

 

The HCH manual says explicitly not to top off the tank. I've found that if you slow the fill rate of the pump down a couple of gallons short of a fill and let it click off, you should be able to get a good amount into the tank without topping off.

 

I fill to the first click then squeeze the pump handle once more, in case the first click was premature for some reason. So I always stop on the second click.

 

Well, now at 246 miles with only one fuel light gone. This is going to be a really long tank, and I don't expect to do it again. Notice how my average is now below 44, that extra gas really killed my mileage (temporarily). This tank will be huge for the extra gas in the pipe, plus I'm getting over 52 on this tank, my best ever by far.

 

I've been topping off on all my cars for >25 years with no problems. The #1 shortcoming of stopping at the 1st click is that different pumps dispense gas at different rates. Some pumps go so fast that you can't slow them down as Ralph describes. I've seen wide variations of delivery speed from different pumps at the same station, while at a few stations all the pumps are high-speed. (Can you tell that I scrounge for the best price? )

If you don't want to top off, I suggest always adding a fixed amount (say 1 gallon) after the 1st or 2nd click, and stick to that routine consistently. That would be the next best way of getting apples-to-apples comparisons.

 

Hi;

I think i'll answer your question like this. I would do it which ever way you are most comfortable with.

Reason for that reply of mine, is because as tbaleno said in his earlier Post here. This has been discussed many times before and it can get real "Heated" very quick. There are very strong opinions here on GreenHybrid concerning this Topic.

Regards;

Terry

 

the reason different pumps at the same station may go different speeds is because all fuel pumps have a filter on it. A slower pump will have a clogged filter if the others are running at a better rate. I have heard some people talking of the pump in the tank needing to be primed and let off for 10 seconds then pump again. If this is true, then maybe the premium or regular tank is needing primed (mid-grade is blended from both at the stations I have worked for). But I would bet 9 times out of 10, that the pump filter is full of gunk (rust, water, etc.) ... The filter is something like an oil filter for your car, and if people pump into thier vehicles while the tanker is dropping off, this clogs the filter VERY fast. One filter can last over a month, but I have replaced them the next day from fill-ups while dropping. Ask them how often they replace their filters. Usually it is not known there is a problem unless the customers complain enough. Just be kind about it .