rza8gamma

I drive a 2006 Lexus IS350. I always fill my car with a full tank of gas. I usually refill the tank when the indicator light come on, but when I refuel the car it only adds approximately 15 gallons of fuel when I know that the car has a gas tank of 17.1. This means that there was 2 gallons of gas that I didn't use. I know you shouldn't wait until you only have half a gallon to refuel, but I like it when my car tells me that its running low on fuel when IT ACTUALLY IS low on fuel. I usually get 360 miles with 15 gallon refuel intervals. How low on E do you guys wait to refuel? do you go by what the needle says or by what the display reads?

DRivera250

iTrader: (6)

that about right. good job on knowing much about you car. the low gas light indicator is designed so you can get to a gas station in time. the low gas indicator comes on around 37 miles under the APPROX MILES. Many people have taken it down to 0 and past. my understanding is that under the APPROX MILES you can still travel another ~60 miles before you actually run out of gas.

shiny250

iTrader: (4)

i think every IS has the same thing. i usually end up filling not even 15 gallons b/c i fill up when the light comes on, unless i just feel lazy. how do you know when you really do need gas? just do some math i guess. if at the approx mile remaining says 0, that probably means you have 1.5 to 2 gallons remaining...1.5 to be safe. if you average about 20 mpg then you've got about 30 miles till close to empty.

rza8gamma

I guess i just need to assume that theirs about 1.5 gallons left after the approximate miles says 0. This is good to know because sometimes when your running late to work you need to make a decisions whether you put gas before or after work.

tastfulmod

I am sorry if this is off topic but is there supposed to be a beep or sound when the gas indicator comes on?

Hoovey689

iTrader: (16)

I've noticed mine does it at 27. It's almost a sure thing. I bet my friend a dollar one time that I knew when the light would come on. Easiest dollar I've ever made lol

Hoovey689

iTrader: (16)

Pretty sure it's just the light. If not then something's wrong on mine lol

syzygy

I've determined that the reserve capacity after you hit 0 miles is almost exactly 2.5 gallons.

If you want, it may not be unreasonable to drive another 10 miles after you hit "0." If nothing else, shedding all of that gasoline weight makes the IS350 noticeably lighter on its feet.

BAMF350

iTrader: (4)

This is interesting to know. I was always under the assumption that if it hit zero it already took in account for the reserve tank.

syzygy

I took my car down to exactly 0 and when I filled up at the tank, I filled up exactly 14.699 gallons of gas.

Exactly (I did not pump in any extra to "overflow", it stopped naturally at 14.699). Well, that's awfully close to 14.7. I presume the car was designed to use 14.7 gallons of gas until the display hit 0.

What's the fuel tank full capacity? 17.2 gallons.

17.2 - 14.7 = 2.5

Very nice, round number.

brociouz

iTrader: (65)

Good info. I hit 0 once and was freaking out trying to find a gas station. Why only another 10 miles after that though? Shouldn't 2.5 gallons bring you a lot further?

syzygy

Yes, you are correct, 2.5 gallons should in theory give you whatever 2.5 gallons will give (say at 20 MPG, another 50 miles?)

But, I've heard in passing that you can potentially damage your car by running on too low fuel (well below when the display hits 0 miles). I do not know the mechanics of this, though. If someone could clarify why (and if) this is the case, it would be interesting to hear.

That's why I said 10 miles. Regardless of whether these claims are true or not (that is, it's potentially harmful to run on literally, say, .2 or .3 gallons of fuel) going an extra 10 miles (half gallon) would still keep 2 gallons in the tank and hopefully avoid these potential problems.

But, once again, I can't even begin to tell you what the potential problems could be, I simply vaguely remember it being mentioned a while back. Hopefully lobuxracer or someone else can chime in.

brociouz

iTrader: (65)

Yeah, I've heard the same thing and was just wondering how you came to that 10 mile figure. Hopefully someone can chime in...

syzygy

Pulled "10 miles" out of my *** . Totally arbitrary haha.

GiantsFan

iTrader: (9)

My indicator comes on with 27 apporx miles left (just like Hoovey)... Never fails. And after its hit zero, my fill up is right around 16 gallons of gas.