I6turbo

iTrader: (1)

From what I've seen, it appears to calculate the averages continually until you reset it. You can push the reset button to reset the modes to 0 and start over from that point.

The LS seems to be very accurate in its MPG calcuations (contrary to some other cars, such as the GX470, which are not accurate). The ECU uses the appropriate variables to make the calculations. It's derrived from the distance traveled and the amount of fuel used (the ECU knows how much fuel is used because it controls the pulsewidth of the injectors, and therefore knows how much fuel is being/has been used).

BTW, my '03 averages about 21 MPG overall, but I don't drive very much in the city -- mostly on secondary roads with speed limits of about 45-65 MPH. I also drive pretty easy when I'm in the LS because I usually have my wife and 2 year old son in there. Some of you guys who are seeing low teens average MPG must be doing a lot of city driving or standing on the throttle a good bit. You should post up your average MPH as well, which would make the comparisons more meaningful if you're trying to compare to other people's LS. If for example you're averaging 45 MPH but getting 16 MPG, you probably have a problem somewhere. If you're averaging 20 MPH and getting 12 MPG, there's likely nothing wrong.

mywong23

assuming you all use OEM diameter tires, has anyone tried verifying the car's stated mpg - by comparing with the old fashioned method?

i.e. refill/top off gas tank; drive couple hundred miles; refill gas tank.
then divide mileage driven by gallons of gas used.....

just curious .....
especially the guys with low mpg.

then I'd suggest adding a fuel injection cleaner, e.g. Techron, in the gas tank;
along with a new air filter.

DanozLS430

iTrader: (1)

I just added the Prestone Complete System Cleaner and added Chevron Premium 92 octane gas. I'll change out the air filter to K&N someime this week and will post my findings. I'm still on my fist tank of gas and only relying on the dash monitor for now. My car just arrived last week and still looking it over.

mywong23

I have no first hand experience with K&N, but many on BMW and Mazda boards say beware that K&N may allow larger particles, in order to claim higher flow...

I6turbo

iTrader: (1)

See my post above -- What I wrote was based on actually testing the LS and GX on several tanks each. The LS' mileage computer is precisely accurate, the GX is about 2 MPG optimistic.

DanozLS430

iTrader: (1)

Question for I6turbo??? When you drive from city to hwy, does you MPG readout on your dash change from 17-25MPG and constantly change according to how fast and how easy you are on your pedal? My car's MPG dash readout stays in between 13.5-14.5 on 20mph drives and hwy 60mph driving. My dash MPG readout never passed or showed above 14.5MPG. I just reset all my MPG settings using my RESET button to clear display 1 and 2 controls on the steering wheel. I'll see what the readout will be after it's cleared. I just got this 2001 LS430 with only 43750 miles on it last week and want to make sure the car is tuned up to Lexus specs.

DanozLS430

iTrader: (1)

After resetting my Display 1 and 2 and drove around the block. I got a average reading of 14.7-15MPG at average speed of 23 mph. My top speed was at 40 mph and mostly coasting and not even pressing on the gas going on a slight down hill. i would think I would get 17-20mpg on this kind of driving. What does Lexus consider city driving to get an average of 18 mpg? It looks like you would be having to be going downhill and not pressing once on the pedal for about 3-4 miles to achieve this. Anyone getting 17-18MPG on regular city driving and pressing on the gas pedal on for and average time when needed?

I6turbo

iTrader: (1)

If the mode is "instant MPG" it's constantly changing depending upon throttle position, engine load, and vehicle speed. If it's in "average MPG" mode, it changes very slowly (unless you've just very recently reset it) because it is taking an average since the last time you reset it.

Yes, see what it says now that you've reset it.

I6turbo

iTrader: (1)

I'm pretty sure mine would get 17-18 or so in mostly slow city driving. However, it's tough to compare what you saw on your short drive. I'd give it a little more time and see what it does. Maybe reset it each time and see what you get on various types of around town trips.

DanozLS430

iTrader: (1)

You would think the car would start off giving close to 17-18MPG even on short drives driving at speeds 20-40mph with a lot of free wheeling coasting and not pressing on the pedal too much. I want to see how much MPG at the best driving method. My tires are at 35psi with stock 16" rims on. I am curious how other LS430 members get 18-20 MPG in city driving. The only way I can see this is driving downhill and not pressing on the the gas pedal for their city miles. My GS300 which is a 6 cyl feels more peppy than my LS430 and gets 22MPG after calculating many refills. Maybe I just need a tune up.....

airtime

I can pretty easily get 18mpg in the city if I go lightly on the gas. These car coast so smooth and easily. From the stoplight, when it turns green, I just have to lightly press the pedal and in about 4 seconds, I'm in 3 gear at 20mph. It shifts fairly quickly to get the best mileage when tread lightly. Trust me, I pretty much drive in the worst traffic here in Seattle / Bellevue in Washington state, where freeway speed avg about 20mph if I'm lucky.

DanozLS430

iTrader: (1)

airtime....When you are driving slow in the city, does your dash MPG readout state 18 MPG?

airtime

Do you mean the current or average setting?

If current, it would be like 8mpg when I depress on the gas pedal then change to 25-30mpg when coasting or cruising. When I switch to the average setting, it would be around 18mpg depending on when I reset it as it averages out since my last reset.

Pure freeway driving, I can get 25 to 28 mpg much of the time going 70mph. The coefficient of these cars are very low, especially when the car lowers itself at freeway speed to get a even better coefficient.

campisi

I concur with what airtime just posted. Mine's a 03 430 and when taking off from a dead stop (mpg indicator in INSTANTANEOUS mode) I get single digit mpg readings but once the car is moving and cruising, even at a slow speed, the mpg indicator is up around 25-30mpg. Highway speed driving easily show 25-30mpg while cruising.
Conserving momentum (keeping your vehicle rolling even just a little bit) makes a huge difference in MPG.

DanozLS430

iTrader: (1)

I reset all my display settings to 0 MPG and when I start rolling it starts off from about 13.5 MPG and goes as high as 15 MPG while crusing at speeds between 20-45 mph around the neighborhood. It did not go up too much even while going on a incline slope and not pressing on the gas. I did not take it on the freeway yet.