how much fuel to keep in tank?

My indy mechanic always advised to work from the top half of the tank not the bottom. No reason I can think of why the advice would be different on with the C.

 

Having less fuel in the tank reduces weight and gets (slightly) better gas mileage. I am not recalling a lot of complaints about people having to replace fuel pumps in their Prius. Without some evidence otherwise, I would favor running on the bottom half of the tank. That said, I just fill when it blinks.

 

I just fill up at 1/4 tank (2 bars) just like I have with all my other cars. Why take chances?

 

The fuel pump uses fuel in the tank to cool it. It is a stressor to your pump to operate at low fuel levels.

I used to constantly flirt with the bottom of the tank, but over time I matured and learned to remove potential disasters from my life path.

 

I think that my new habit will be to fill the tank around the half-way tick.

 

I fill up when the light comes on. I have always done that with every vehicle and have never had to replace a fuel pump. That does not mean its not bad for the pump - I don't know where the fuel pump sits vs the level of fuel when the light comes on, but I would assume that Toyota would make the light come on sooner if there was going to be a potential issue to the fuel pump. I do see a lot of old car myths still being used today even though the technology is significantly different. I believe that the though that running on E can damage the fuel pump refers to consistently running on E, or driving for another 50 miles past the low fuel light every time. If your fuel light comes on you still have more than 1 gallon in the tank.

 

I'll be filling up more often, not to protect the fuel pump, but because I want to track my mileage info at Fuelly more frequently.

 

I try to fill up at the end of each week, which is about a half a tank. Sometimes I don't get around to it, but I do then try to do it at 2 to 3 segments. The higher the better because as Mr. Incredible says above the fuel is also a coolant for the pump motor. I have run it down to one segment a few times to see what the fuel warning indicator looks and sounds like.

 

How many watts of cooling does a fuel pump need? How cool does the fuel pump need to be? How little fuel do you need to have before that amount of heat will raise the temperature to a point where it can't adequately cool the fuel pump?

 

Me too. I think it's a good practice. But never wait till it blinks.

 

Since you are so inquisitive on this subject, why don't you test this out for us and report back ?

 

When the refill indicator illuminates, how many gallons does it take to reach full?

9.5 gallons is the capacity. If it only takes 7 to 8, there's nothing to worry about.

 

Yes, Gen II got a bladder gas tank( strange design). No one knows exactly it's capacity. Some said it's 10.7 gal and some said it's 11+ gal.
So the vise way is to refill the tank when it's half or a bit less.

 

Not that strange really. Aircraft use bladder tanks so it in not a new technology or anything. Although I suppose the reason to use it is different though.

 

I still can't get my head around you guys choosing when (and how much) to fuel up. This is my reality:



Down here fuel-up day chooses you.

 

I add fuel after it rains and I want to get the discount for the car wash.

 

As a motorcyclist, I can tell you that motorcycle fuel pumps in the tanks are frequently above the fuel line. I've even had a couple of bikes that had exterior electrical, not mechanical, fuel pumps which according to old school thought would have died almost instantly since they are never submerged in fuel.

Another data point: since the volt, under ideal driving circumstances, can go months without using fuel, the owners manual actually advises keeping a 1/3 of a tank as a fuel economy tip.

 

Oh wow... the fuel companies here are now totally mocking us and our consumer regulator which was completely unsucessful in getting them for collusion, even after raiding their offices for documents.

I lucked out this week in the local fuel price lotto game - flew back into town on Tuesday and filled up, managing to hit the bottom of the cycle dead on. Two days later on Thursday the price at my local station was 16.7% higher than I had paid, now taking it to the equivalent of US$6.32/gal.

No-one was batting an eyelid any more to the 10% changes in sort-of-weekly cycles, but this finally got them back in the news... upping it to 16 day cycles and a big increase in the spike.

Petrol's spike driving us crazy

 

If this were true, OEM's would mandate you fuel-up prior to a certain level in order to negate such risk and retain warranty coverage. As we know, they don't demand such thing. OEM's design the fuel system to operate at low fuel levels, I know this from 1st hand experience working in the automotive industry. Add in fuel slosh and subsequent intermittent starvation when you take corners and it means in-tank fuel pumps are rather robust devices. Most ECU's have fuel rail pressure and fuel temp sensors as part of the control strategy; and if either of those are askew the computer understands how to react to not further damage components.

This isn't a license to be an idiot and run your tank dry every time. Arriving at the refueling station pushing your car is hardly graceful or time efficient. Likewise there's no reason to refuel with half a tank remaining when you could've stopped in a few days or whatever at the next available station. Refueling more often than necessary is also time inefficient and also gives more opportunity to release fuel vapors into the atmosphere.