SoonerDave

I'm a newb in the Lexus world, and just bought a 2015 ES 350. Love it like Bugs Bunny loves carrots. Drives like an absolute dream and its just plain stinking awesome.

The one curiosity I have about my car is this: When the gas gauge nears E and the "Driving Range" slides to the 30-50 mile range, I expect a tank refill to take about 14-15 gallons (given ~17 gallon capacity), but it usually takes only 12-13. I know that topping off the tank once the filler shuts off is a big no-no, but a 12-13 gal fillup implies I'm shorting the tank a good 3-4 gallons. Is the cutoff happening too soon?

I was a little concerned about possible evap problem, because one generic vehicle driveability issue wherein the gas pump cutoff hits prematurely is a possible EVAP cannister problem. No codes on my car, no real problem, just an observation that it seems to click off too quickly.

gamma742

This is a common complaint with this year/model Lexus. There is nothing wrong with your new car.

Poppa

I did not know that topping off the tank once the filler shuts off was a big no no. Lordy, I've been topping off the tank on every car I've owned ( including my ES ) for years and never experienced any issues.

Roland

ludecrashr

NdYAG

There is about 2-3 gallon reserve left in the tank when it starts showing empty. It is typical for all Japanese cars AFAIK.

SoonerDave

If you overfill the tank, the excess liquid fuel can go to the evap cannister and ruin it. The evap system is supposed to control pressure in the tank (driving and at rest), so if the system can't bleed pressure as you fill it, the level can go high and cause the pump to shut off prematurely; thus, if you force (top off) the tank, that overflow goes either out the nozzle or possibly into the evaporator cannister. A spoiled evap cannister sets a code and has to be replaced...

All that said, the risk varies with vehicle and evaporated system design, I think. I've topped-off my wife's Sienna and my former Buick Lesabre for all the years we've owned them with no problems. But I also know the tolerances for the emission systems gets more finicky as time goes on with newer cars, so who knows.

lesz

The 2-3 gallon "reserve" is definitely the reason why the the gauge shows "empty" and the car's computer shows "0 miles to empty", but it only takes 15 gallons at the pump to fill the tank. That has been the case with every Toyota or Lexus vehicle that I've owned.

Tootsall

nuraman00

Even when within the 7 - 20 mile range when it would say that's how many miles the driving range had remaining, I don't think I've ever seen more than a 13 point something gallon fill up.

The capacity is 15.9 gallons, not 17.

https://www.lexus.com/models/ES/specifications

lesz

But the manual says that the fuel capacity is 17.0 gallons.

It is on page 520 of the 2017 ES manual. For other model years, the page number may be slightly different.

nuraman00

You're right. So what to believe, the manual or the website?

lesz

I have no idea why there is a difference between what the manual says and what it says on line. My first guess was that the manual includes the reserve capacity, and the internet link doesn't, but the reserve is somewhere between 2 and 3 gallons, which is bigger than the difference between the two stated capacities.

From my own experience with 2 Generation 6 ES's, I'd say that the capacity including the reserve, is pretty close the 17 gallon number.

Poppa

I normally fill my cars up when they reach 1/4 tank.. hardly ever let them get below that, but the other day, was short on time so I passed the gas station... when I did stop, the low fuel indicator was lit on the dash... I topped it off and it only took 14 gallons. add that 2 to 3 gallon reserve and you're right there at 17. makes sense to me.

Nelexus88

I have put in over 14 gallons a few times in my '14 ES 350, but I try to avoid running it that low. This happened when the gauge was showing E and the low fuel light was ON. I do not know how much of the remaining 2-3 gallons in the tank is usable as the fuel pump may not be able to pick up the gas when the car is on sloping ground and the tank is not level. In my experience the miles to empty hits 0 before the low fuel light comes on, so you have several gallons remaining as a safety factor.
Running the gas level low can also shorten the life of the fuel pump as it depends on the fuel for cooling.

mcomer

I used to "top up" my wife's '99 Solara SE with the 3.0 V6. As mentioned above it
lite the Check Engine light at around 35K miles. Evap Canister need replacing for
about $400!

Basic answer to the thread question is that the gauges are "pessimistic" and report
a lower level than actual to minimize likelihood of running out of fuel. I experimented
when I had an urban commute that had a dozen gas stations and it was summertime
in case I had to walk. Drove for a week after the light came on and the meter was
pegged on "E". Range would only report "Low" Weaving the car didn't budge the needle.
When I finally filled up (without topping off!) it took 2 gallons less than stated capacity.