Fuel Range (or Miles to empty)
 

Does anybody know how this is calculated? I got in my car to drive home yesterday, I checked my range to see if I could make it home and it said something like 88 miles. I thought, awesome I should be able to make it home no problem. But only a few miles down the road it read 67 miles, which was really pushing it. Has anyone else noticed a lot of inconsistency with this?

I also read on the TL forum that when the mileage gets to around 0, you still have a few gallons left. Is that the case with the RDX as well? I've noticed I should be on "E" but only put in about 13 gallons out of a 16 gallon tank, so I assume it is similar. Unless it doesn't really hold 16 gallons unless you top off the tank, which you're not really supposed to do. Just curious.

yes. there is a few reserve gallons, as you noticed you're only filling up with 13 gals instead of the full 16 gals.

also, i think the fuel range is instantaneous.
use more pedal, use more fuel, etc.
go up a hill, use more fuel and the fuel range would indicate that.

Doesn't really seem instantaneous sometimes. Even when I'm just pulling out of the gas station and getting like 10 mpg it's telling me I can go 450-475 miles. I rarely make it past 350 before the fuel light comes on. Weird.

i mean, isnt it logical that the more gas you use the less range you're gonna get?

Between trying to guess at the reserve amount and the fact that I have added 1-3 gallons more than once with no change in the range, I just plain don't want to push it when the tank gets very low. DW, on the other hand, has been known to bring the car home on 'flatline'...zero miles left:what:. Of course, I'm the one trying to make it to the downhill stretch to reach the gas station when she does this. I still don't think I've put significantly more than 14 gallons in...even when the gauges show 'bone dry'.

I've mentioned before, back in Atlanta...we didn't dare go much below 1/4 tank for fear of getting caught in a 4-5 hour traffic gridlock and running out of fuel! It's a bit more relaxed here in central Texas:thumbsup:

I think somewhere in the manual it says that the fuel light comes on when there is about 2.5 gallons left. So, the range when the fuel light comes on should be current MPG times 2.5.

On a recent trip I stretched my luck and drove 496 miles on one tank of fuel. I was averaging a little over 30 MPG. I put 16.353 gallons in the 16 gallon tank. I didn't top off the tank.

Good luck, Jim

The range (i believe, I could be wrong) is actually not set up to go to the last drop. I can't find it in the RDX manual, but I remember in my old TL it said the range would run out and then you would have a "reserve" amount of gas left, which was basically 1 gallon. I believe the RDX is probably set up like this as well.

I think the range is based on your average mileage on your current tank of gas. So it can change while driving, if your driving pattern changes. For example, if you've been driving in the city for 70% of your gas tank, and get, say 18 miles/gal, but then you go on the highway, and your gas mileage goes up, your range will increase. This has happened to me, where the range increased after driving a few minutes on the highway. Or maybe it's based on a weighed average, ie, your average mileage of the last 5 min, or 10 min, or something similar. I don't think it's based on your current (instantaneous) average, because I don't remember the range varying a lot while driving.

Same here from Chicago to Savannah, GA I average about 29+MPG and about 450 miles between fill ups. Better than my 2007 RDX. The best I ever saw on the 07' was 26MPG.

I fill up every 400-450 miles

Are those Canadian miles?:what:
Unless I'm just cruising at low highway speeds, I'm much closer to 330-350 per tank. I miss REAL fuel tanks, like our former '04 V70 Volvo with a 21 gal tank.:annoyed: ('course we also had a Miata, so it all balanced out:tongue: ).

^^Agree. I can set the cruise on 65 and travel a hundred miles in flat Illinois and not hit 36mpg for the trip. Maybe 30-31 if I'm lucky and don't have to slow down or speed up much for traffic. Maybe this is imperial gallons or somebody is smoking something. A vehicle rated 27AWD/28RWD is just not going to get 36mpg unless you're going downhill or drafting a semi the whole way. I drive mostly suburban and my computer says 24.2 at about 6k miles. I consider that too be just great considering the combined mpg for my RDX is supposed to be 22mpg and I drive pretty conservatively. If I'm late for something I might push it a little hard but most of the time I'm in no big hurry at all.

I guess I missed the post where someone claimed 36 mpg?:toocool:

Regards, Jim

I drove my RDX down to 6 miles to empty, thought I was on fumes but she only took 13.5 gallons.

I think it was in the "real mpg" thread.

Smoking something?
 

Yes, it was in the "real mpg" thread, and I don't smoke. 36 mpg one way and 32.8 on the return trip. Maybe my computer is off but I'm not.;-)

I added my range to however many miles I've driven since my last fill up. My point was it always overestimates my range regardless of my mileage, until I get about under a quarter tank and it drops suddenly.

Not sure what you mean by "I added my range to however many miles I've driven since my last fill up."

Anyway, I just set trip A to reset on every fill up. I have left trip B to manual reset. That way each tank of gas has a current range and mpg, and trip B is a long time average mpg.

Regards JIm

Does anyone else find anything wonky with the fuel gauge calibration? It seems like I consistently get ~250 miles by the time the gauge reads 1/2 tank and ~125 miles before the needle starts getting close to E...

I do the same thing. What I meant was....let's say Trip A says I've driven 200 miles, and my range says I've got about 200 miles to go. Add the two together and that's the total mileage for a tank.

Thanks for the clarification. Yeah, I think an earlier post asked about the apparent difference between the first 250 miles and the next 150 miles. I have noticed that the range and the fuel gauge seem to decline faster on the second half tank.

Regards, Jim

It automatically calculates by the amount of fuel & the mpg you're getting on your trip.
During a road trip everytime i "punched it" for a few miles you'd see the range drop drastically & then if i cruise controlled it , it would stabilize.

It's more personaly preference, i leave the range visible for driving normally but during road trips i leave the mpg calc

related question
 

Hi,

I have a related question. I just recently bought a 2013 RDX. I filled the tank for the first time, soon after the big yellow low-gas screen came on (wow, it's hard to miss that one!). I was surprised that the car only took 12 gallons. Is that typical? Does the warning generally come on with 4 gallons of gas still left in the tank? Or did I just stop pumping too early? (I did not stop pumping until the auto-shutoff kicked in).

Gregg

Spot on! Most of it was highway and I got 699 kms (434 miles) and it took 60.5 liters. Obviously the tank must be larger than the advertised 60.5 liters.

As for mileage remaining, I believe they are conservative. I don't have the numbers in front of me but my Excel spreadsheet has two extra columns. One with the calculated distance remaining and the other the indicated distance remaining.

My low fuel warning comes on when it's showing about 40 miles of range, and I've filled up several times with it showing 30 miles range but never put in more than about 13.8 gal. I've been a bit underwhelmed by MPG so far, and the computer seems to over-estimate that by just over 1 mpg. Best tank was about 26 MPG in almost entirely highway driving with ~75mph cruising speeds. Costco premium is usually within a dime of everyone else's regular, so I give it the good stuff...

Almost exactly my experience (a few weeks in on a used '14). Warning comes on around 40 and typically allows about 13.6 gals if I fuel up immediately; actual mileage is always about 1 mpg below computer. I did get 28+ on one tank, almost all highway. No 91 octane here in NE Florida, so I kinda mix 93, 89 and sometimes a little 87. I'm sure it averages to an adequate number...