Another data point: The last time the gauge said 2 miles DTE and it only took 12.5 gallons (265 miles on the tank). This tank, I drove another 50 miles past 0 DTE and it took 15.5 gallons (315 miles). So yes, seems like the fuel gauge is VERY conservative. Almost to a fault.

 

This will be a lengthy in-put, but may answer some of the questions out there, so bear with me. We purchased a TX 500h Luxury in mid Apr of this year, so this is a six month evaluation of what we have from a numbers perspective. Our original search was for a 550h, but we were quickly dissuaded from pursuing that after being told it would probably be a year wait, and even with the 500h Luxury (test drove & came close to buying a 500h Premium) it took a three month wait after finding an allocated (not built, & not spoken for) vehicle at a dealer 160 miles from our residence.

A little background; I’m the primary, and generally a conservative driver (don’t have a “heavy” foot), but will usually be somewhere at 5-10 mph over the posted limit. We live in the St. Louis area (IL side of the river), and I’m a retired engineer who’s admittedly a little bit of a “numbers nerd”. Additionally, a lot of the “non-town” driving is on typical 2-lane 55 mph highways, with the rest on “in-city” 4 or more lane interstate highways (60 or 65 mph limits). So, with the exception of “road trips”, I don’t generally drive speeds over 70 mph. I also always drive the TX in “ECO” mode, although I’m not sure what the changes in vehicle performance are from the other “modes” (??).

The vehicle we replaced with the TX was a 2009 Honda Pilot Touring with all the bells & whistles available at that time (purchased Oct 2008). So, going on 17 years old and 250K miles last Apr, it had been a very reliable ride (many ski & general road trips hauling lots of “stuff”; people, skis, golf clubs, gifts/plants going both ways in addition to multi season luggage), and had some features that I actually think are better than the TX (GPS display with a “scale” so you could estimate distances, and a joystick so you could move to a point on the map ahead of your current position to see how far out it is, etc.). Most importantly, it could hold my entire foursome with their golf clubs along with a cooler for a round in the area, generally within 100 miles. It used “regular” fuel, generally got 22-23 mpg on a road trip, and would consistently get over 500 miles range on those trips with a completely full tank (close to overflowing, takes a little longer to fill), which translates to roughly a 22-24 gal in an advertised 22 gal tank (never went past “0 range”, so actual volume never measured). I say that because of the concern in these forums relative to the size of the TX tank, particularly the 500h’s (17 gal). Contrary to the Pilot which could display “instant” milage, the TX has an electronic display efficiency meter that I try to keep the ‘blue needle” to the left of the 12 o’clock position, and generally below the 10:30 position when possible (“light” on the gas petal). The 9:00 position being the differentiator between all electric & combo elec. and gas.

All that leading up to my “stats” (the “numbers”) to date (six months and 7,315 miles through mid Oct). In addition to tracking the “total miles”, “trip miles” and “avg mpg” at every fill-up, I also began recording the “remaining range” beginning at 1,600 miles which gives me a hack on the total miles I would have achieved on that tank of gas, that when combined with the “avg mpg” yields total gallons (“tank vol”). That said, like the Pilot, I’ve never pushed beyond “0 range” (closest was down to 4 miles), so I don’t know what remains in the tank at “0” (anyone??).

Assuming a “full” tank (??) from the dealer (paperwork said 4 miles on the vehicle, odometer said 18.3), I got anywhere from 24.5 to 27.0 mpg on the vehicle read-out at the 1,326 miles point (top-off for “road trip”) with each subsequent fill-up slightly higher than the last (engine break-in?). That translated to a calculated (miles / total gal purchased) of 26.3 mpg avg. through the start of that May/June road trip to Texas which was 2,125 miles in length (round trip). That trip was mostly interstate highway driving with some “in-town” driving at the 4 “visit” stops we made, and resulted in a calculated total avg. of 27.0 mpg. Since then, all of the driving has been in the immediate range of our home with the conditions described above. At the 5,000 mile point (30 July, actually 5,009 miles) that included everything to that point, the milage average was again 27.0 mpg. Since then, to that 15 Oct fill-up which included a lot of hot summer weather (AC on), the avg milage has been significantly increasing (again, engine break-in?) to an avg for those 2,306 miles of 29.7 mpg with that last fill-up being 30.4 mpg! It should be noted that I also do a calculated milage at each fill-up, and that is usually around a half mpg lower than the displayed mpg. Also, since that mid-Oct fill-up, the milage now showing is only around 26.5 mpg for about 130 miles of almost all in-town driving.

As noted, I also calculate a “Trip + Range” number at each fill-up, and that has varied from 425.0 miles at 1,747 miles (1st after recording “remaining range”) to 460.7 miles at 7,315 miles (last fill-up), for an avg of 439.8 miles for those 16 fill-ups over 10 gal (a couple of just top-offs not included). As also noted, at each fill-up, I calculate a “tank volume” using the actual volume filled plus the “remaining range” divided by the calculated mpg (not the displayed mpg). Doing this results in a tank volume low of 14.70 gal and ranges to a high of 17.18 gal for those same significant fill-ups, or a 15.59 gal avg. Not having taken the vehicle below “0 range”, does this mean there are approximately 1.4 gal remaining at “0 range” (approx. 35-40 miles?), or is the tank smaller than the specked 17 gal (???).

To summarize, we’re generally very pleased with our 500h to date, and have been surprised at the actual milage performance numbers being as close to (exceeding?) the advertised numbers. Even though we’re using more expensive “premium” gas (91 or 93 octane, a seperate debate vs. “regular"), we’re still doing better on a $s per mile basis that what the Pilot did. So, we’ll see where these numbers go over this coming winter (a couple of lengthy road trips planned).

 

It's not... I filled up 17.0 gallons yesterday. The filler is very reminiscent of my Toyota FJ cruiser which will click off well before the tank is actually full.