Minimum miles per fillup?

welcome to priuschat! you should be able to use 10 gallons with a couple more to spare as a safety measure, but your bladder is acting strangely as a small number are prone to do. is your gauge showing full pips after filling up with only 6-7 gallons? winter is usually a factor, when did you purchase it?

 

It helps to leave the gas cap off for a minute before starting to fill. Some pressure equalization in the system allows more fill.

 

Elwin,

First of all "Welcome to Prius Chat".

I imagine you have read by now how the bladders expands and contracts with temperature variations. I also understand your desire to be able to purchase more fuel than you are to utilize discounts from your grocer.

I too fall into that category of using the discount. So I do understand what your train of thought is.

I only have two suggestions to you.

1. Consider carrying an additional five gallon fuel can and fill it while you are filling the Prius. I must state that this is not a "safe or wise" practice but will allow you to purchase more fuel at one time.

2. This is the better suggestion in my opinion. If you have not done so, take the time to learn about hypermiling the Prius. You will be amazed as to how much of a difference this technique will save you money as well as lower your dependence on foreign oil.

There are links in my signature below which will point you to a site on cleanmpg.com which covers the technique. You will also find come next summer that your bladder will hold a considerable larger amount of fuel as well as your MPG will be higher. Depending on how you drive your Prius, you can easily extend the range well past the figures you are reporting now.

Regardless of any action you do or don't take at this point, just getting the Prius like you did has helped to conserve and lighten the load on your wallet.

Best of luck to you and again "Welcome to Prius Chat!"

 

and after you've let it depressurize, pump as slowly as possible, this sometimes keeps it form shutting off too soon. i see that as it's gotten colder, your fill has gone down, so hopefully, it will begin to increase next spring. it also helps to try different pumps, but i suppose you are limited to the supermarkets.

 

I second bisco--fill it up at at slower rate--the first click on the pump trigger. It doesn't take too long--it doesn't hold much.
With consistent first-click fill-ups, I've always averaged right around 7.5 gallons to fill, regardless of season.

 

Most gas pumps have multiple catches on the trigger handle for filling at different rates. The first catch for the slowest fill rate seems to work well. Don't top-off once the pump clicks off.

A little hypermiling definitely extends the mileage on each tank. With some practice, you'll be posting 450 mile tanks in no time. I read of someone completing a 700-mile tank once but that involved extensive hypermiling and white-knuckle driving with a flashing last pip.

 

Plus one for the pulse and glide hypermiling. I learned it with a few morning drives to work. Used it to ensure 51 mpg at 20F snowy condition as well as hit 70mpg for the 30 minute drive in decent conditions. Current average is 52 for 190 miles and 4 pips left. Have been used to 46-48 mpg this winter

 

Last week, I was getting about 45 mpg, and put 11 gallons in a fill up. Somehow I managed to run out of gas (in the desert border of West Texas/NewMexico). I think it was because I was enjoying the sunset. Anyway, my cousin brought be a gallon of gas (in her prius, so she knew I just needed 1 gallon) from 25 miles away. I was the talk of the family reunion. I got 450 miles on that tank. It took about 4 power on-off cycles to start, and I was reaching for the owners manual when it started up.

The next tank got me less than 400 miles (9 gallons) before it ran out. That's right. I did it again. But this time, I limped into a station on battery power. But this time, I remembered the important thing: Don't tell your family.

 

You will get 45 mpg regardless of when you fill up. You can fill up when you have 2 pips left and still get 45 mpg. You can fill up with half a tank remaining and still get 45 mpg. But you filling up when you are out of gas, still gets you 45 mpg and can damage your car (not to mention getting stranded)

 

Yes, expensive damage. There should have been some posts to read about running the tank down to near empty which allows the fuel pump to rise out of the fuel (a coolant in this case) and possibly overheat resulting in premature failure. And you can't replace just the pump. The entire tank assembly must be replaced. $$$ and maybe $$$$.

 

Seriously?!! I did not know that - will having 2 litres of fuel left in the tank at fill up prevent damage from happening?

 

I tend to drive till the last pip "squeaks" (squeals?)......and then it's an automatic divert to the nearest fuel station. There's always one within 3 miles of my location during my commute - 5 miles max, but I'm guaranteed to make it. All fill ups with the last pip flashing indicate there's still about 2 litres left in the tank.....I should be okay, right?

 

And yes, I fill up much sooner in Winter - last pip or two - before it switches to reserve.

 

You know, I'm not 100% certain on this. Others might back me up. I can't say I have seen the actual orientation of the fuel pump in respect to the rest of the tank/bladder and at what tank level the pump might be getting exposed. The bladder would tend to contract and eliminate voids, but I think the pump and gauge are located in a portion of the bladder that isn't as flexible. Somewhere on PC, or maybe an external link, there is an exploded view of the Prius gas tank that someone documented taking apart, but even that really doesn't show the particular parts. I just consider the replacement cost and keep a half tank or better at all times.

 

Thank you. Just for the record, I seem to recall my mileage per tank dropping to a lowly 540 miles during the deep of Winter. Not too bad methinks. Still much more than the measly 180 miles from the same 43 litres of fuel I got out of my otherwise ultra reliable 1998 Mazda MX-3 during the same winter season. Our UK Prii don't have the bladder in the fuel tank, so fill ups are very consistent.

 

@Data Daedalus, what AzWxGuy/JC91006 have said is mainly applicable to the US Gen II with the flexible bladder. In the UK, as you are, (and probably any other market) it does not really apply.

When I'm gunning for the "how many miles can I get per tank" scenario, in the UK I would never fill before getting the beep and flashing last pip, accompanied by the "Please add fuel" message on the MFD. On the beep I reset my trip 'B' milage meter to ensure I have an accurate record of my milage. I endeavour to fill by 50 mi, but in one instance I was starting to sweat at 70-ish mi. I did not run out of petrol then, and fuelled up with 44.xx litres, so was getting close.

By all accounts (at least as verbalised here on PC), this technique cannot be safely employed in the US due to the foibles of the flexible bladder tank in the Gen II. But rest assured it works very well in the UK.

hope this helps.