Actual Fuel Tank Capacity

CBS · July 17

Hello all.

I have a 2023 RX 350h.

Does anyone ever get close to the claimed 65l fuel tank capacity.

If I run it to less than 20 miles indicated range I can only get about 50l in. This should mean I have 15l remaining. I am reluctant to run it past indicated empty but wondered what others experience.

I am based in the UK if it makes any difference!

Thanks
C

Spock66 · July 17

Pretty sure the fuel tank capacity is correct, but the estimated range is deliberately conservative to prevent you running dry which amongst other things is not great for the car.

Tickedon · July 17

Some of us have the same issue with the NX :

wharfhouse · July 18

17 hours ago, CBS said:

Hello all.

I have a 2023 RX 350h.

Does anyone ever get close to the claimed 65l fuel tank capacity.

If I run it to less than 20 miles indicated range I can only get about 50l in. This should mean I have 15l remaining. I am reluctant to run it past indicated empty but wondered what others experience.

I am based in the UK if it makes any difference!

Thanks
C

Seems the same for all Lexus / Toyota - on my IS 300h when the on board computer reads zero miles remaining there is still about 10 litres left in the tank - that's enough for close on 100 miles... Never put it to the test but have run for about 10 miles beyond zero miles left! On my wife's Toyota similar story - that has a smaller smaller tank than mine but similar percentage left in the tank when zero miles is displayed. It's a nice fall back position to have when looking for a petrol station.

mikey2001 · July 18

I have a 2019 RX450h which has the same size fuel tank. I don't routinely do this, but there was one occasion in the Scottish Highlands when I drove about 40 miles beyond the point at which the on board computer said there was 0 left, and when I finally stopped to brim the tank I managed to put in just over 60 litres. But this would mean there was still over a gallon (in old money) left, good for another 35-40ish miles based on my average fuel consumption.

CBS · July 18

I was going to ask if anyone has driven much past Zero but mikey2001 has answered. Looks like we are OK for a few miles past empty.

Thanks for the replies

C

Herbie · July 18

Why are people bothered about how much the tank actually holds?

You should never let it get anywhere near running dry; it could be a very expensive lesson to learn, especially with hybrids.

The fuel pump sits immersed in the petrol for cooling purposes so not enough fuel to cover it means the pump will begin to run hot, which is not good. You could also drag up crud from the bottom of the tank and block your filter.

For hybrids you need a minimum of 10 litres in the tank before attempting to start the car and if you have three failed attempts the hybrid system could lock out and you would need to get the car to a dealers for them to reset it.

I never let my car get below an indicated 1/4 full, it's just not worth the risk. And to be honest, with todays maps like Waze, Google Maps, Sygic and others that easily show you the location of and distance to almost every filling station in the UK, there's frankly no need to let your tank run low.

GSLV6 · July 19

^^^^^

This

Tickedon · July 20

On 7/18/2024 at 9:19 PM, Herbie said:

Why are people bothered about how much the tank actually holds?

Why am I bothered? I used to have an Audi with the smaller 40l tank, it meant I couldn't do my 500 mile round trip or my 440 mile journey to Scotland on a single tank, I'd always have to fill up somewhere.

I bought the Lexus NX on the understanding it would have a 55l fuel tank, and thus between the Battery and fuel I could stop having to think about fuel ups. I run my vehicles on premium fuel, and my preference is to save a small fortune by using Costco's premium fuel whenever I can - thus having a larger tank to fill up is incredibly helpful to keep my costs low. My journeys are also almost exclusively short local journeys (EV is perfect for this on my PHEV) or long trips around England and Scotland.

A key technical specification (size of a fuel tank), as advertised by Lexus, doesn't seem to be available to me and plenty other drivers. It's also not like it's a small proportion - in my case, when the car tells me the tank is nearly empt, I can only get approx 32l into a 55l tank. That's only 58% of the capacity. If I kept it above a 1/4 tank as you do, that means I'm topping up every 240 miles or so... hardly great for a car like this!

On 7/18/2024 at 9:19 PM, Herbie said:

For hybrids you need a minimum of 10 litres in the tank before attempting to start the car and if you have three failed attempts the hybrid system could lock out and you would need to get the car to a dealers for them to reset it.

I've seen this referenced in a couple of places - do you have the technical source for it please?

Spock66 · July 20

I have found on every car I have had that has an estimated remaining range feature that it is deliberately conservative.

If my lawnmower runs out of petrol, no problem I just fill it up and prime the carb and starts again first pull. A modern electronically managed car is not so simple, any debris in the tank is likely to clog the fuel pump and injectors and I suspect you may have problems priming the fuel system too.

I would imagine that you also need to factor in if the car is on a steep gradient or hard cornering that the fuel will move around in the tank and at some point you would get fuel starvation.

Herbie · July 20

1 hour ago, Tickedon said:

I've seen this referenced in a couple of places - do you have the technical source for it please?

It was a long time ago so it may be a while but if I can find it again I'll happily post it here for you.

Herbie · July 20

Here's the first part and I'll keep looking for the hybrid lockout info:

Illogan · July 20

On 7/18/2024 at 9:19 PM, Herbie said:

Why are people bothered about how much the tank actually holds?

<<>>> there's frankly no need to let your tank run low.

It's great to see a solid dose of common sense!

Steve44 · July 27

Tank also has a very slow fill and when pump first clicks off, I can usually get another gallon at least in it, with big air gurgles as it fills. So in my view, it’s a conservative range estimate, and a poor tank design, means short fills and more trips to the petrol station. It is 65ltrs though I have had that in it a couple of times.

Steve44 · July 27

On 7/20/2024 at 8:57 PM, Herbie said:

Here's the first part and I'll keep looking for the hybrid lockout info:

Is that for a RX5? Pic is for RX4

Herbie · July 27

4 hours ago, Steve44 said:

Is that for a RX5? Pic is for RX4

That is indeed for RX4 but I'm sure the principle is the same.

brendangeorge · August 2

On 7/17/2024 at 8:20 PM, CBS said:

Hello all.

I have a 2023 RX 350h.

Does anyone ever get close to the claimed 65l fuel tank capacity.

If I run it to less than 20 miles indicated range I can only get about 50l in. This should mean I have 15l remaining. I am reluctant to run it past indicated empty but wondered what others experience.

I am based in the UK if it makes any difference!

Thanks
C

Hi The tank capacity is the first fill capacity - there is part of the tank you cannot use. Sound daft but...