Kampfhund

I have a 2018 RX 350 F-sport and I typically get 300-310 miles per tank. I understand that cruising range isn't very accurate and doesn't account for the reserve fuel remaining when at "0 miles". I'm just curious about what other people's cars say they should get on a full tank most of the time. Thank you for your responses!

dibl

The answer depends on the miles per gallon of gas, and the miles per gallon depends on the type of driving that you are doing, the weight of the load etc.

The fuel tank is 19.2 gallons, according the user manual, p.700. You won't drive it until it runs out of fuel -- let's say you are very certain of your remaining fuel, and are able to drive until there are only two gallons remaining before you refill the fuel tank. So, you are able to use 17.2 gallons. (The "Low Fuel" light and warning messages on my car come on when there are about 3 gallons remaining.)

My worst mileage is in short city/suburban trips with lots of stops and some time idling -- about 19 mpg. My best mileage is on the freeway with cruise control set -- about 26 mpg. Normally there are one or two people riding in the car.

So, worst case is 17.2 x 19 = 327 miles. Best case is 17.2 x 26 = 447.

arrowroot

Whenever I fill up until the pump "clicks", the remaining range showing when I drive away from the gas station is consistently 480-482 km (300-301 miles).

dibl

Drive it until the Low Fuel light and warnings come on. Then fill it up, and make note of the amount of fuel needed to fill it completely. Compare that number to the fuel tank capacity specification for your model. Doing that will reveal the amount of fuel remaining in your tank when the warning light comes on. I was surprised when I did that, and asked my dealer's technology advisor about it. He said "Lexus really, really, really does not want you to run out of fuel."

Dhaka

I ran out of gas several times in my first-gen RX350 to the chagrin of my wife. I have become much better now.

dibl

My understanding is, with the fuel pump inside the gas tank on these newer models, running out of gas is likely to burn out the fuel pump, resulting in a tow bill and an expensive repair. That's probably why the low fuel light is set so conservatively, so you have lots of time and miles to get more gas.

Schweden

I really wish the range estimate were more accurate. I track my fuel usage manually using an app and I can consistently get 28mpg+ (8.4l/100km) on highway trips. If the fuel tank is 19.2 gallons (72l), then I should be able to go 850km+ (530 miles). But the highest my range has ever shown was just under 700km (440 miles). By comparison, my former Subaru and BMW often showed a range of 1,000km+ (620 miles) when refilling after a lot of highway driving.

yok3dIS

Not sure if this helps but tend to get between 300 to 325 on a full tank. However, I fill up when its down to a quarter tank either early in the morning or late at night. So maybe an additional 20-30 miles on top of the reserve?

dibl

There's probably 4 gal. in your tank at that point, so depending on your mileage, you've got 50+ miles before you need to start worrying.

mckdaddy

The fuel range estimate after refueling falls around 406-410 on my ‘20 450, fwiw.

bamalam

Out of curiosity I did this test today. I ran my 2020 RX350 down until it reported 8 miles of range left. The fuel gauge needle was right on the Empty indicator. (The low fuel warning came on at 24 miles of range remaining.) I'd driven 361 miles on the tank, and the car was reporting 22.7 MPG, so in theory it had less that 1/2 gallon of fuel left.

I let the pump auto shut-off work and had it set for low flow, so that splash-back wouldn't cause a premature shut-off. (Hate when that happens...) It only took 15.72 gallons, whereas the tank capacity is 19.2 gallons, according to Lexus. While it is unlikely you could ever draw all the fuel out of the tank before the engine shuts off, it certainly does appear that there is a significant safety margin built into the fuel gauge and warning system. My guess is it is at least 1.5 gallons and maybe as much as 2.5 gallons, or 30-60 miles. (Don't count on my tests while your're driving across the American West. I'm not an automotive engineer nor an expert in fluid dynamics. )

Lastly, one of the variables in such an experiment is the sensitivity of the the auto-shutoff in a given gas pump. To do this test right, it needs to be repeated with a few different pumps.

dibl

Today, my "Low Fuel" light came on, and I was within 1 mile of my favorite Shell gas station. So I pulled in and filled it up -- after the nozzle clicked, I went ahead and added to the next whole dollar. It took 15.0 gal. For a 19.2 gal. capacity tank (according to the user manual), that computes to 4.2 gal. in the tank when the Low Fuel light came on. If you want to protect the fuel pump by reserving 2 gal. at all times, that translates to about 50 - 60 miles before you really need to gas up, after the Low Fuel light comes on.

mckdaddy

Jealous of your 19.2 gal tanks, as my ‘20 450 only has a 17.2 gal tank.

New450hL

Right at 400 miles per tank of highway cruising at 70-80mph

TBurns

Yes but with our 17.2 gallon tank we get around 500 miles per tank. Most of our driving is around town.