Fuel low light - game of nerves :-)

[Lost it]

Good to know... I just picked up my first Lexus RX. So I'm going to be lurking on here for a while to see what I can learn.

[genkakuzai]

So, today, about 30 seconds from when I was about to refuel, the low fuel light came on. And I could fit almost exactly 51 liters.

Conclusion: Since the tank has a capacity of 65 liters, the light comes on when there's 14 liters left. 100% certain of this now ^^

[AdAlbert]

Hi everyone, RX450h 3rd generation 5 liters (1.5gal) of fuel tank capacity can not be used at all for engine safety reasons. There is only 60 (15,8gal) litres of real tank "capacity".

The light goes on when 10 litres left BUT it means only 5 litres you can use - 60 km (37miles).

I know that for sure. I ran out of fuel yesterday. The combustion engine stopped. EV went on for few hundred meters. I put 5 litres in tank. Went to nearest gas station and fill the tank until full - 55 litres.

So 75 miles from the moment when light comes up is NOT TRUE. It is half - 37 miles.

[AdAlbert]

On 6/2/2019 at 6:56 PM, genkakuzai said:

So, today, about 30 seconds from when I was about to refuel, the low fuel light came on. And I could fit almost exactly 51 liters.

Conclusion: Since the tank has a capacity of 65 liters, the light comes on when there's 14 liters left. 100% certain of this now ^^

No, I am sorry, but not exactly true. Maybe the light goes on, when 15 liters is still in there in rx400h. But you can not use 5 litres at all.

I got RX450h and the light goes when 55 litres can be filled. But you can use only half of the rest 10 litres.

To me the RX400h solution is better, because it is standart, that 10 litres is still there to use in the tank. Same as Mercedes etc...

[AdAlbert]

On 5/27/2019 at 4:47 PM, TimS320 said:

I’ve been having the same thoughts as the OP. 

Just in the middle of a holiday across Europe and over 3 full tank fills only managed averges of 320-330 a tank. Only got the last up to 345. The RX handbook states the tank is 65 litres but I’ve not managed to get more than 52 litres in. I always used to assume 1 gallon left when the warning light came on in all previous cars but I am sure this is a lot more. I also can’t get more than 30 mpg on the autobahn, even when trying for an economy run.

However unlike old VWs I don’t run this right down unless absolutely necessary. Only time I had this recently was coming down the A1 from Newcastle to Manchester one night when one services was blocked off for a night closure and the next only had diesel! Pulled in to the third one on fumes, having done 30 miles after it showed zero. Like others, I still couldn’t get near 65 litres, 59 was all. So is there 5 litres of fuel in the tank unused?

On another thought, I’ve been crosschecking the trip computer in the car with two satnavs as we were bored and had a 1000km run to make. When getting an Average Speed indication it is usually 5pmh less than the speedo. The satnav shows in the middle of the two, which is correct as the car speedo should always over read to prevent speeding.

However I wonder if the lower computed averges might have any affect on the really low average MPg I have just got over the last 3 fills of around 28-30mpg.

So is there 5 litres of fuel in the tank unused?  YES YES YES I guess it is safety reason not to damage the engine.