Dear Lexus Owners,

I recently bought a 2015 Rx450h and seem to be having some issues. The car as such is excellent but will like to bring it to everyone's notice that it seems like the car is overstating the mileage. I brought this up to the dealership and also to lexus corporate. The corporate asked me to send the vehicle for inspection to the dealer and when inspected the service manager stated the onboard computer needs a break in period till 2500 miles and then will show the right mileage. Currently I am having around 2450 miles on this vehicle since the delivery on 09/16/15. This sounded really stupid to me as how can a computer show something different to what its programmed too and need time to think? Agree about the break-in period. But shouldn't it show the reality of what its supposed to show??

The lexus states this vehicle gives avg 29mpg [28 hwy and 30 local]. I am using premium fuel either from shell/mobil/exxon. The onboard computer as soon as a tank refuel shows 400mpg as estimated mpg. The Avg mpg after refuel shows 26 to 27mpg while the odometer reads really less with only 3 bars for tank to empty out. I took some pics and enclosing on forum. The current Trip odometer reading shows 279.2 miles, cruising range left 105 miles and avg mpg after refueling 26.5mpg. This car has an tank capacity of ~17gallons. Adding 279.2+105 = 384miles. Divide this by 17gals and the mileage is 22mpg. how on god can I state 26.5mpg. If this were to give 26.5 as stated it should have been 451miles for a tank that till date have never received.

There is some serious issues either the vehicle computer is misleading us or something funky is programmed just to overstate. With all the vehicle manufacturers scandals feel this is one more. Did some research on internet and found that Honda did something like this in the past [2007 or 2008] where they were overstating the odometers and mileages. A class action law suit was started then and did lose as it was valid.

Please all other owners owning this check this out and please help me to report on this thread. It is really necessary to expose as customers to put an end on something that is this bad and stop scandals. I will comply to something that is stated as acceptance vs. something misleading.

 

You cannot calculate based on how many bars tank to empty is showing. You have to calculate based on your actual fill up.

Step 1: Reset trip A odometer to zero.
Step 2: Drive until next fill up.
Step 3: During fill up take a reading of how many miles was driven and how many gallons you filled up with.
Step 4: Calculate, divide actual miles driven by actual gallons filled up.

In some cases computer doesn't include reserve amount in miles to empty calculations.
For example in your case it could be 384 miles /14.5 gallons (17-2.5 reserve)=26.5MPG
Good luck.

 

"Cruising Range" on the display doesn't include the buffer. If it says you have 105 miles to empty, you actually have quite a bit more. There are at least 2 gallons of reserve left when you get to 0 miles left. So at 105 miles to empty, you probably have 150 or so actual miles remaining. You can't calculate mileage off of that value.

As stated above, you have to go off actual gallons you fill up with.

 

Should not this poll be in the hybrid forum section.

 

Moved.

cnplkart, have you taken a look at the 450h mileage thread? Probably not since you posted in the wrong subforum. That thread covers most of your 'issues' and I quote issues because you have made some very serious allegations. I'd suggest you take a look through it, educate yourself on 450h owners' mileage experiences, including our different driving situations (i.e. city/highway driving, even/hilly roads, outside temperature, etc.). Then reevaluate your statements. The break-in period is exactly that, a time for adjustment. And for you too.

 

Could be worse, you could have bought a VW diesel.

 

Been through this many times flying general aviation aircraft. Analog fuel tank gauges are notoriously inaccurate. The Digital MPG is more accurate. You don't want to ever run out of fuel in an aircraft because it can ruin your day.

I suspect when your fuel gauge is bouncing on zero and your miles till empty reads zero you probably have about 2 gallons reserve.

I've been tracking MPG for years on at least 10 cars. Almost every one overestimates MPG by 5% EXCEPT My RX450h. My RX450h lifetime (only 2,000 miles so far) MPG dashboard digital display is 27.9 and when calculated with a pencil, the real MPG is 27.8 MPG. Click on the small picture of my RX450h in my signature for details.

If you really want to dig further click on the link under this sentence here for reported actual MPG from 54 RX450h's
http://www.fuelly.com/car/lexus/rx450h