gundy

Just wondering how accurate the trip info computer is on my 2005 RX330. I just returned from a road trip and at one point, according to the computer, was getting 28mpg on the highway driving normally (i.e. not attempting to "hypermile" anything). I thought the max for this model was around 23mpg(?). It did seem like ~65mph was the sweet spot for max efficiency.

alchemist

iTrader: (1)

Sounds about right.

LophatRX

Haha, I have averaged 28 going from around Victorville to just about the first major climb headed towards Vegas, doing about 75 during that stretch, without tail wind either.

gundy

Also forgot to mention mine is AWD. Regardless, if the trip info is correct and 28mpg is relatively easy to attain, then why wouldn't Lexus rate the highway mpg as 28 instead of 24? It appears the city rating of ~18 is accurate.

JProdun

Sounds right going 65. I got that as well on a long drive

ho0n

I believe part of it has to do with what fits as OEM parts (i.e. tires, roof racks), but I'd also venture that Lexus thought it'd hurt the company more to be found to overrate MPG than it'd benefit the company to please customers with underrated figures. I might even guess that marketers use underrating as a cushion against the indeterminate cost of further improving fuel economy on future RX models.

Is that going too deep? I don't know.

jfelbab

1. The trip computer is seldom 100% accurate. Perform your own testing to determine how accurate the computer is. Mine was always low.

2. Most drivers of the RX330 don't achieve 28 MPG over an extended period of time. My own RX330's AWD MPG over 10 years of driving: Minimum 17.2, Maximum 28.7, Average 23.1.

On 100% expressway I'd typically get 25-27 MPG measured but I'm a high MPG achiever and these expressway trips were predominately run with the cruise control set around 70 MPH on relatively open expressways covering some 18 cross-country trips. I achieved 28 MPG or better only twice in the life of the vehicle and that was burning 91 octane pure gasoline (no ethanol).

Some other driver experiences:
2004 RX330: http://www.fueleconomy.gov/mpg/MPG.d...rue&details=on
2005 RX330:http://www.fueleconomy.gov/mpg/MPG.d...rue&details=on

From looking at these other vehicle reports, in general, the EPA estimates seem reasonably accurate.

How the EPA estimates arrived at: http://www.epa.gov/otaq/carlabel/doc.../420f06069.pdf

gundy

Gotcha, though we're talking 2004/2005 here when I don't believe fuel economy/conservation was as big a deal as it is now. However, now, with fuel economy a huge deal, we often hear about companies who have overstated the MPG for their cars including Toyota ( http://left-lane.com/toyota-sued-mis...ybrids-europe/ )

DPJ

I have a 2004 RX 330 and drove 85 mountain highway miles and averaged 28 MPG. I may have stopped a couple of times and left the motor running as well. I filled the tank with premium and drafted a truck carrying a prefab house. I could actually feel him pulling us at times. I also turned off the AC during some of the steeper climbs. I don't think I'll do it again as it's a little bit of a risky way to save $5. We are normally getting 19-24 MPG on Regular.

takeshi74

Do the math and compare. I find our RX 400h has a variance of anywhere from 0.19 MPG to 3.29 MPG.

Figures are based on standardized testing -- not what may or may not be "easy to attain" (which can vary with a number of factors).