Yes, we have gas with up to 10% ethanol only around here. I use Shell.

I forgot to mention I used the dynamic laser cruise control as much as I could during the drive. I'm sure that helped a bit combined with eco mode.

 

Can anyone tell me the most accurate way of measuring the mpg on my Rx450h? I see on the center display there's a mpg reading for "after refueling" and one that says "average" mpg. My MPG after refueling hovers around 30-31 mpg, while my average says about 26.5. Which is more reliable? Thanks in advance

 

With over a year in my car now, I can say the readouts are accurate, they sometimes very just a few 10ths either way (never more than that) and I know that from comparing their readings to miles driven VS gas pumped.

I haven't 'zeroed' the total average since the 1st of June and it's 28.9 today. I'm very happy with that as many of the miles are just 2-4 and then shut it down. Yesterday I drove about 275 miles round trip on state roads and highways with stops as I went through small towns and stints of 10-15 miles at 60mph on cruise. My average for that trip (since fill up) was 31.8 and I'm very happy with that.

But your average miles will change somewhat week to week (due to variables in your driving/traffic/errands) so the only way you'll figure it out long term is if you leave the average going for long term, as in several months. It will be accurate enough to to say you get XX.X MPG.

 

FYI, I have found the "after refueling" to be quite variable for the first 1/8 to 1/4 tank, then the calculation settles down and approaches the cumulative "average." In my case (in hot/humid Tampa), after 3500 mi, I am averaging about 28.5 mpg (mixed city/hwy driving) using Shell 93 Octane (has 10% ethanol). I'm hoping to see a bit more improvement as we get into (slightly) cooler weather.

 

instead of using the mpg figure...how much miles have you guys driven before you have to fill?

 

Ha Ha, that's a good one. My situation is maybe a little more unique than others. Being retired I can usually time fill-ups with the rise and fall of the price of gas. Many times I can fill up at the lower price point, watch it go up and not have to fill up again till it's back down . That might be 75 miles or 300.

BTW, I'm also someone that always gets a receipt and keeps it till at least the next cycle just in case I get unlucky enough to get bad gas, I can prove where I bought it.

 

I usually fill back up when the low fuel light comes on and about 40 miles left on Cruising range. Usually in the 370-400 mile point till refill.

 

damn that is a lot..I've been getting around 340.

 

How may gallons do you put in at this point?

I ran mine until the Cruising Range stopped providing a number but was only able to get 14.8 gallons in the tank on filling. That means that there was 2-3 gallons in the tank which should have taken me another 40-60 miles.

I generally just fill when I get below half a tank.

 

I've always had a bad habit of letting the low fuel light come on before I pull over to get gas, and even then I'll drive it another 20-30 miles before I fuel back up. I was reading the 450h's manual and saw that it said that these hybrids are not designed to be driven on low gas (or words to that effect). Do you all think that's just standard language that all car manuals include (maybe for liability reasons), or is there something about the hybrids that make it especially important to fuel up before the fuel level lights comes on?

 

Not sure, maybe a combination of both

The 450h is not designed to run on electric only. A few other hybrids can. Some people may be under the impression all hybrids are the same. I remember my sales person telling me that I couldn't drive the RX on an empty tank. Now I can't remember when or by whom but I was told early on not to run out of gas. Obviously it stuck because I never have. And then there are some that push the limits figuring there is a 2-3 gallon safety net. It's nice to have the cushion but not me. I'd rather be safe than sorry.

On the 450h I fill up long before the light goes on with anywhere from a quarter to half tank left. But that's still only about half the amount of times I used to gas up. Plus it's cheap by me and I can't pump my own

 

About the same.. 14.5-15 or so. i don't think cruising range is spot on.. i might try to push a little further next time and fill up when it hits E.

 

Also something to note. In any car, its not really a good idea to go as low as possible on fuel before refilling because any trash in the gas tends to settle to the bottom of the tank, and if you run it very low, you stand a chance of picking up some of this trash and clogging fuel filters, injectors etc.

Also, never get fuel at a station that is having its supply refilled by a tanker. When they fill the tanks, it stirs up all the trash from the bottom.

 

Ditto on both . Except for when on a trip I rarely go below 1/4 tank from empty. Personal experience in that area .

 

i get 420miles till the low fuel warning light comes on