RX - 3rd Gen (2010-2015) Discussion topics related to the 2010 - 2015 RX350 and RX450H models

Fuel gauge accuracy ...

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Old 08-25-12, 06:59 PM
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MachineMan
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Default Fuel gauge accuracy ...

Filling up the car when it the needle is a liitle above Empty and the Driving Range shows about 50 miles left .... I can only get about 13 gallons into the tank no matter how I try to get in more ... What can you get ino the tank when at Empty on the gauge?

Also the needle does not drop below Full until after about 125 miles ...

2013 with 1250 miles
Old 08-25-12, 08:53 PM
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RXSF
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its not a matter of accuracy of the needle. Its a matter of keeping a buffer for you so that you dont run out of gas
Old 08-26-12, 12:05 AM
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UCSB
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When the car reports zero miles to go and empty, you still have additional fuel. I checked it once last year, but can't remember how many gallons remained (I think it was about 2 gallons on my 450h). The car's emission system can be damaged if you run out of gas and so Lexus is doing everything within their power to help prevent that from occurring. I consider it a feature. I have never viewed the fuel gauge as accurate in terms of what % of the tank you have remaining ... it is just the way it is.

Last edited by UCSB; 08-26-12 at 12:11 AM.
Old 08-26-12, 04:43 AM
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Cruiter
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The fuel gauge in a car is just that, a 'gauge'. Based on experience over several tanks it allows you to gauge how much fuel is left. True readings are used in aircraft where 'meters' determine how much fuel is being used. We wouldn't be able to afford those probably and then we'd have to be constantly calculating how much further we could go.

Some cars may be more accurate than others, but to find one that shows the needle moving proportionately with the exact amount of gas remaining is pretty rare. Just learn to judge by filling it up and what the needle showed prior how much you have.
Old 08-26-12, 05:36 AM
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BertL
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I think in another recent thread, folks believed there was something around 2 gallons of gas left when the gauge shows empty. For as long as I can remember, all of my autos have taken a similar approach telling me I was empty, when I really had a little more to go. I always fill up before that, but would be surprised if my car just flat stopped when it first approached the big "E".
Old 08-26-12, 05:22 PM
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fr0mastaj
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Once the gauge goes to E, there is still ~4 gallons left. When you fill up from 'empty', it will need approximately 16 gal. The fuel tank capacity is 20 gal.
Old 08-26-12, 06:13 PM
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BertL
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For hybrid readers of this thread, be careful, as 2013 RX350 fuel capacity = 19.2 gallons, but the hybrid 2013 RX450h fuel capacity is significantly less at 17.2 gallons. My 2006 RX400h had the same 17.2 gallon tank. While it's lifetime MPG was roughly 23-24 MPG, there is no way I could have approached nearly 100 miles after hitting the big "E"... Probably more like 50 miles max once the truck indicated I was empty, and hopefully a few miles more in my new 2013 once it is broken in and the MPG continues to climb. I'll hopefully never know, as "3/4" is the time I start looking for a fill-up.

Last edited by BertL; 08-26-12 at 06:25 PM. Reason: Added 2013 broken in addition
Old 08-26-12, 10:04 PM
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RXSF
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I just had the yellow gas tank light come on and I drove in town for another maybe 10 miles. I was averaging around 26.8 miles on that tank of gas according to the computer. I ended up putting 14.6 gallons in the car. so even when the light comes on, you have 2+ gallons
Old 08-26-12, 11:08 PM
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Sevn86
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Mine seems pretty accurate.
Old 08-27-12, 05:54 AM
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tfischer
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Gas gauges are always reading high, and I'm sure the manufacturers don't want to err on the other side.
I do not put a lot of miles on my cars, so I always have the time to fill up at no lower than the one-quarter mark. Besides never running out of gas, this practice eliminates the low gas anxiety syndrome, symptoms of which appear in the posts above.
Old 08-30-12, 05:33 PM
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Johnny
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Originally Posted by fr0mastaj
Once the gauge goes to E, there is still ~4 gallons left. When you fill up from 'empty', it will need approximately 16 gal. The fuel tank capacity is 20 gal.
Whaaat? Four gallons is a quarter tank, which will easily get you 75 miles. I've run the needle down to the line, and when it crosses that line, the car has less than a half-gallon. I've run out of gas many times in the past - I like the exercise , but I've found Lexus cars to have very accurate fuel gauges compared to other makes. So when when I'm on the line, I start looking hard for gas...
Old 08-31-12, 06:25 PM
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MachineMan
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Default I should have been more specific ... what I meant to say is that at less than 1 mark

past the Empty line the car will accept 7 gallons at fillup. I've been buying cars since 1967 and understand there is a couple gallons reserve capacity in the gauge calibration. The gauge should NOT read near empty when there is 1/3 tank of fuel remaining. Range remaining shows about 50 miles at that point .

Last edited by MachineMan; 08-31-12 at 06:27 PM. Reason: adds
Old 08-31-12, 07:00 PM
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dctex99
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Originally Posted by MachineMan
past the Empty line the car will accept 7 gallons at fillup. I've been buying cars since 1967 and understand there is a couple gallons reserve capacity in the gauge calibration. The gauge should NOT read near empty when there is 1/3 tank of fuel remaining. Range remaining shows about 50 miles at that point .
I certainly agree; Lexus guage is pretty wacky; my wife is one of those that panics when it gets to 1/4 tank and I have yet to put in over 12 gallons; I am curious to take it on a long jaunt and see if it is more accurate; lately mostly around town and averaging about 20 MPG!
Old 09-02-12, 04:15 PM
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Evitzee
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When the RANGE gets to zero you have approximately 2 gallons left in the tank. Have done this numerous times and I can jam in enough fuel which is always 2 gallons short of the stated capacity. Lexus has a bath built into the tank so the fuel pump is always in fuel even if the tank is empty. If you run out of gas your pump is still sitting in fuel so it won't burn out. It may have been a problem with older vehicles but is not an issue with current Toyota's/Lexus'.
Old 11-18-13, 07:29 PM
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Yurka
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my full tank's range varies between 245-250 depending on how aggressive i drive. Usually my mpg is about 12-14. when i was going on a road trip to Canada, since its only highways for the most part my mpg went up to 33mpg and when i filled full tank range went to somewhere between 280-300miles.


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