almost_g

Anyone else notice a large difference between what the car reports and what you calculate at the pump? My IS consistently reports 10% higher MPG compared to what I calculate at the pump!

Also, when would you typically expect MPG to improve following break-in? 2-3k miles? 5k miles?

I'm almost at 2000 miles now and I'm not getting as good MPG as I expect... Thanks

al503

My computer is consistently optimistic (between .4 to 1.2 mpg) than what I calculate by hand.

Make sure that you are refueling at the same pump when calculating as each pump might shut off a little sooner or later depending on it's sensitivity.

You're MPG's will continue to get better as you break in the car.

tex2670

Car is telling my 1-2 mpg higher than actual. By the way, my mpg sux. I'm getting b/t 19-21 (even though lifetime mpg meter says 22). I have AWD, and I do a lot of stop and start driving, so I didn't expect 26-28, but I at least thought 22-24.

Allen K

iTrader: (4)

1-2 MPG high seems about right. I get about 23 mpg because I do a lot of short trips.

Bass Mech

the few times i have checked mine it has been almost dead on within 1 MPG ive seen it high and low so for the most part i think the average is close enough.

Gernby

iTrader: (1)

This has been my experience as well. FWIW, the calibration of the gas pump could be to blame, or even the climate conditions at the time you fill up.

xerxes717

Mine is also mostly off by a little bit ~10%.

My lifetime average is 19mpg at 2500 miles on the odo

Orzel

iTrader: (1)

IS 250AWD, lifetime is now at 24.8 and we regularly see 30+ MPG on the road. Have found that our readout is very close when we gas up at the same station/pump. We're sitting at 16k miles now, and have been watching the fuel mileage gradually increase since about 5k.

rroy

iTrader: (1)

my IS reports 2 mpg higher (on average) than my calculations...

Recluse

My car reported figure is 13 MPG. That would be a serious downer if I am actually getting 11 MPG-12MPG.

Gernby

iTrader: (1)

If you are being serious (and honest), then there is something wrong with your car. That is getting close to road course mileage.

chums

iTrader: (3)

!! sorry to hear!

xerxes717

+1.

I drive my IS350 reasonably hard and mostly around town, that's why I have a lifetime avg so far of 19 mpg.

When I drive like a crazed maniac on steroids in the mountains, I've averaged as low as 10.8mpg over some runs, but that's only because the car is pretty much constantly on redline for extended periods of time. I don't know how anyone could possibly have a lifetime avg of 11-13...

GordoNx3o9

My lifetime average is around 17.7 for the past month. I always thought my MPG is too low. Tank average usually stops at 16-ish before filling up again. I do a lot of city driving but 16 I think it's too low.

Recluse

I am being serious and honest. The car just topped 3000 miles, and while San Francisco driving is definitely challenging, I definitely don't drive like I'm on a road course.

Just to clarify, my "tank" average is normally about 13 MPG with typical driving (it's a little higher now, because I did some highway driving over the weekend, and it went up to 16 MPG, so it's on its way back down now), and my "lifetime" average was 15.3 MPG the last time I checked it.

I mentioned it when I was last at the dealership, and they didn't didn't seem to think there was anything wrong with it.

This is less than I was getting with my old car (Z3), which had a larger engine, more HP and torque, one fewer gear, and was driven hard every single day.