micio

Hi Everyone, I was reading a lot of threads about mpg on an IS350, and it seems that the average is at least 25mpg.
I bought an 08 IS350 new and now I have 1200 miles on it, at 1100 miles the Control VSC light came on and I had to take it to the dealership to get it checked.
It was a Oxygen sensor ( i can look for the exact code later on today) and they fixed it under warranty.
After 40 miles I got the light again, and they said it was a second Oxygen sensor.
I really only drive in the city, but the MPG is around 15 max 17mpg...
I was reading that some people had bad mpg during their break in period, but I thought after 1k miles it would do better.
Do you guys think there is something else wrong with the engine?

Thanks!

Allen K

iTrader: (4)

How hard to you accel and brake? Are there a lot of stoplights on your normal route? A lot of things can come into play when doing local streets. I decided to take a local route to work today (bad decision) and I averaged 22 MPG

micio

Gentle accelerations and approx 6-10 miles distance each time, around 4-5 lights. Max speed 50mph.

If I drive on the beltway i can get 25mpg, but never better than that.

slee18

iTrader: (1)

Mine is just a 250 but after the second oil change i noticed a MPG started to inch up every thousand miles. I just recently installed a JoeZ intake with a K&N drop in filter had have about a 2 MPG increase all around.

see how it does after the first oil change. FYI I changed over to synthetic oil on the second oil change.

vrferrari

Bad 02 sensors can really play havoc on your fuel economy. How long ago did you get the 2nd 02 sensor replaced ?

suicidesam

i get 17mpg...reason is i drive the ect pwr + pedal dance on and with the paddle shifters less mpg but a lot more fun

micio

Around 1100 miles the first and 1140 the second, i found the paper for the first repair:

Cause: Short Circuit
895131 Oxygen Sensor (one)
223 W
1 89467-30010 Sensor , Air Fuel Rat


980 REPL BANCK 2 Sensor 1 895131 1.30

Which sysntetic oil do you guys use on your IS350?

k_dizzle

wow. i dont know about you guys but i get 25mpg on my is350. and i def dont drive slow....yet not too fast either; unless i have to

leo_k

i get 19mpg on my is 250AWD... i drive with ECT on PWR and i use the paddles/semi-auto ... not ALL the time but ALOT... the ECT is always on though, if i feel it slow a little i turn it off...drive for 10 mins with stops and starts (not highway) and then turn ECT back on and it gets a JOLT... so..i know why i get 19mpg... hehehe

IS_250

iTrader: (2)

quit beating on your 350!

Have you reset the MPG indicator after every fill up?

vrferrari

So these were very recent repairs. If the computer is anything like other Lexus products, I would disconnect the battery for 1/2 hour to clear any "learned" driving habits and codes from the ecu and give it another shot. A shorted 02 sensor probably kicked your engine into a very rich mode, which also might explain why the other 02 sensor failed.

Omnivor

Have you tried recording distance traveled at fill-up time and do a simple division yourself to check?

sykocus

iTrader: (1)

Depending on your driving habits 15mpg city isn't out of the realm of possibility. When I first got my car i was probably getting between 16-18mpg. However given your history already I wouldn't rule out mechanical issues.

vrferrari

18 city/25 hwy is what the new EPA figures are for IS350 and average driving habits.

kayotik

iTrader: (6)

did the joe-z intake really make THAT much of a difference?