Mpg Gauges ?

[123guy]

I have a 2008 RX 400h with navigation. Current miles 396. Bought it July 14, 2008.

It has two mpg gauges; one on the instrument cluster under the speedometer, and the other in the trip information section of the navigation menu. The owner's manual indicates that the former "Displays the average fuel consumption since the vehicle was last refueled." The latter has a reset button on the screen (no comment in the navi owner's manual). My intention is to use the cluster gauge to determine my mpg for each tank and the navigation screen gauge to keep the cumulative mpg.

Despite the words in the owner's manual, the cluster gauge does not appear to reset after I filled up for the first time.

Can I accomplish that with the two read outs some way?

Thanks for your help.

[jrober]

I wish the 2 separate mileage indicators would record separately so you could keep track of both intermittent and cumulative mileage. Unfortunately I haven't found a way to do this. They both reset when you hit the reset button on the nav screen. I have been writing down my mileage and odometer setting every time I hit the reset button so I can manually keep track of my cummulative mileage. I will probably get sick of this after awhile.

Congrats on your new vehicle.

[s10]

I have a 2008 RX 400h with navigation. Current miles 396. Bought it July 14, 2008.

It has two mpg gauges; one on the instrument cluster under the speedometer, and the other in the trip information section of the navigation menu. The owner's manual indicates that the former "Displays the average fuel consumption since the vehicle was last refueled." The latter has a reset button on the screen (no comment in the navi owner's manual). My intention is to use the cluster gauge to determine my mpg for each tank and the navigation screen gauge to keep the cumulative mpg.

Despite the words in the owner's manual, the cluster gauge does not appear to reset after I filled up for the first time.

Can I accomplish that with the two read outs some way?

Thanks for your help.

The MPG indicators are not very reliable. Much better to calculate fuel consumption by hand by resetting the odometer to zero everythime you tank...

[123guy]

I wish the 2 separate mileage indicators would record separately so you could keep track of both intermittent and cumulative mileage. Unfortunately I haven't found a way to do this. They both reset when you hit the reset button on the nav screen. I have been writing down my mileage and odometer setting every time I hit the reset button so I can manually keep track of my cummulative mileage. I will probably get sick of this after awhile.

Congrats on your new vehicle.

Every other new vehicle I've bought, I have started keeping track of mpg manually. I know that it is an indication of lots of things. I'd love to know what it is over time. I thought that it would be pretty easy to keep track here. I guess I'll have to choose between mileage tank at a time or some other logical unit.

Thanks for the information. We feel good about the first tank 27.1 mpg

[RX400h]

I'd say that's a big improvement over the 17-18 MPG that the RX350 owners are getting!

[123guy]

I'd say that's a big improvement over the 17-18 MPG that the RX350 owners are getting!

Yes, it is!! Thanks to you and the LOC for the hints that I read prior to taking delivery of the RX. One off thread comment because I find it interesting. Because of where we drive, we have noticed some differences from what I have read about. Already, I have completely charged the traction battery several times (it happens on the loooong downhills here in the mountains). When you achieve complete charge the RX uses the traction battery and electric motor(s) instead of the gas motor at much higher speeds. I've pressed the accelerator and had it use the electric motors at over 50. On our trip to Breckenridge, CO we drove the eight to nine miles from Hoosier Pass to Breckenridge without using the gas engine at all, even though there were several periods where we were not coasting. :D

[RXREY]

I wish the 2 separate mileage indicators would record separately so you could keep track of both intermittent and cumulative mileage. Unfortunately I haven't found a way to do this. They both reset when you hit the reset button on the nav screen. I have been writing down my mileage and odometer setting every time I hit the reset button so I can manually keep track of my cummulative mileage. I will probably get sick of this after awhile.

Congrats on your new vehicle.

Every other new vehicle I've bought, I have started keeping track of mpg manually. I know that it is an indication of lots of things. I'd love to know what it is over time. I thought that it would be pretty easy to keep track here. I guess I'll have to choose between mileage tank at a time or some other logical unit.

Thanks for the information. We feel good about the first tank 27.1 mpg

I've never, in the three years of having my 400h, have gotten less that 24MPGs and my previous best was 27.1....UNTIL today...a whopping 27.56MPGs. I do it on paper so it's accurate. But for the most part I get around 26. I do mostly in-town driving. The fact that this last tank went to 27.5 was because I had longer drives and anyone here in L.A. knows that the traffic is often slow and allows for not only the car to be very warmed up but also many slow coasts which make the MPGs go up,up,up. Rey Bustos in L.A.

[s10]

I had never reset the mpg indicators, so they were still considering the initial 2000 miles... it indicated 24.3. Now the car has 4000 miles, so time to reset... which I did yesterday and am curious to see what the new mpg indication will be like.. if it is near my own (on paper) calculations.

[RXREY]

The on board computer is always generous by around 3% but since I have 255/55 tires, or 3% bigger, I factor that in and my calculations and the computer line up pretty closely now. This last tank the computer said 27.6 and I calculated 27.56...tenths are as close as the computer registers....so it worked out the same. ...just to remind all of you, that's the best MPGs I've had since I bought the car almost three years ago. I drive normally, carefully, but not granny-like. I really do think that the L.A. freeways are PERFECT for hybrids. I am lucky, I don't have to commute but lately I have been on the freeways more and it really pushes the MPGs up. It's the constant traffic here that makes the hybrids do great. I used to get so mad in traffic..partly it was the waste of gas just sitting and moving 20MPH then stopping,moving 20-30...etc. Now it really has made a difference in my emotional state! I'm basically in golf cart mode for miles. Rey

[SOMEONE ELSE'S GOT MY NAME]

If you truly want THE killer gadget to moniter (everything from) fuel consumption, mpg (to SOC, engine temps, ad nausium) and more, then get yourself a canview. You can get 'em with a simple led readout, or hook 'em up to a DVD screen as a moniter source:

http://hybridinterfaces.ca/trips.html

Heck, Ive even seen one geek hook it up so it would read right through the MFD. They continually upgrade their systems, for newer hybrids, and they even upgrade their hardware on occasion. You'll have enough data to destract you right off the highway

Enjoy

ps, rxrey I find your 3% accuracy about right. But turning on one drive or the other, for us, that 3% might be high OR low. And when you're talking (liberally) 30mpg ... well heck that aint much ... maybe 1/2mpg or less.

[RolandB]

We have a 2006 RX400h that was the second hybrid delivered here in Dallas by our dealer. Overall, we've been satisfied except for mileage. We currently have 167 spreadsheet entries regarding gasoline. The lifetime rating has 22.56 MPG. The indicated MPG on the display is usually around 5% higher than actual. The most interesting experience is our performance in Colorado in the Denver area. Our consumption rate improves dramatically by around 15%... I can't get any dealership (Dallas or Colorado) to give me an explanation. My conclusion per a friends suggestion is that the computer does a more efficient job in that mountain's higher altitude. I always 'Reset' the mileage indicator when I refill the tank. My refills are usually done in the same manner. I am a strong 'cruise control' user and hope that properly applies the accelerator when needed up and down the road.

[SW03ES]

Consider though in an RX330 you'd probably be getting 15MPG...

[shrewsburyite]

We have a 2006 RX400h that was the second hybrid delivered here in Dallas by our dealer. Overall, we've been satisfied except for mileage. We currently have 167 spreadsheet entries regarding gasoline. The lifetime rating has 22.56 MPG. The indicated MPG on the display is usually around 5% higher than actual. The most interesting experience is our performance in Colorado in the Denver area. Our consumption rate improves dramatically by around 15%... I can't get any dealership (Dallas or Colorado) to give me an explanation. My conclusion per a friends suggestion is that the computer does a more efficient job in that mountain's higher altitude. I always 'Reset' the mileage indicator when I refill the tank. My refills are usually done in the same manner. I am a strong 'cruise control' user and hope that properly applies the accelerator when needed up and down the road.

The air is a bit thinner, so there's a lower partial pressure of oxygen. Thus, there's less fuel (osygen) to burn, so it burns less fuel (gas). The difference is probably made up with the battery, so you won't see a change in performance. [i'm gunna get it for this]: The 400h does have a TAD more power than it needs! The barometric pressure is around 30 inches.

Anyway, as a half-baked chemist, that would be my answer. (I still deal with pressures on a frequent basis)

[katzjamr]

also, dont different states use different additives and blends of fuel? could it be that the fuel blend in colordado provides better gas mileage? it is well documented that premium fuel results in higher mpg (about 3 mpg) than regular, in the 400h. what is the octane rating of the fuel u buy in colorado vs your hime state? is there more ethanol in one than the other. it seems to me all these things would affect mpg all other things being equal. dave

[jrober]

" it is well documented that premium fuel results in higher mpg (about 3 mpg) than regular, in the 400h"

Complete bs. Please show us this "well documented" proof.

[Better Luck]

I have a 2008 RX 400h with navigation. Current miles 396. Bought it July 14, 2008.

It has two mpg gauges; one on the instrument cluster under the speedometer, and the other in the trip information section of the navigation menu. The owner's manual indicates that the former "Displays the average fuel consumption since the vehicle was last refueled." The latter has a reset button on the screen (no comment in the navi owner's manual). My intention is to use the cluster gauge to determine my mpg for each tank and the navigation screen gauge to keep the cumulative mpg.

Despite the words in the owner's manual, the cluster gauge does not appear to reset after I filled up for the first time.

Can I accomplish that with the two read outs some way?

Thanks for your help.

I am reading the thread, no one answered the poster's original question about resetting. I was curious about this as well since my Prius reset within driving one mile after a fill up all by itself. I have not found this to be true in my 400h. Any concurrences?