Hey guys,
i have a 09 IS350,
it has ridiculous fuel consumption​​​​​
i dont knw if it's normal but for 23 Litres its giving me 100 Kms (62 miles) if driven at low rpm, or 70-80 Kms per 23 Ltrs on rough driving.
it doesn't seem normal to me,
a workshop told me it was bcoz i of catalysers, i changed both the catalysers (bank1 & bank 2) n it didn't make 1% difference,

no rough idle so plugs n coils look good to me, any help would be really appreciated
thanks in advance


the car is completely stock, no aftermarket exhaust system, stock intake.

 

Start by cleaning the MAF sensor with MAF sensor cleaner and replace the air filter. You should also clean the charcoal mesh in the air filter box... https://www.clublexus.com/forums/is-...-interval.html

When done, run some fuel system cleaner through it.

What grade of petrol is being used, low octane fuel will impair fuel economy?. Buy the best fuel available.

 

PS my 350 gets 21 to 23 MPG doing a mix of city/highway.

Range of 300 to 325 miles (482 km to 523k)
14 gallons @ fill up (53 liters)

312.5 mi / 14 gal = 22.3 mpg
502.5 km / 53 l = 9.48

 

^ After all that maintenance. Reset the ECU to wipe LTFT's clean. If possible get a Bluetooth adapter to check fuel trims. It takes about 50-100 miles to be emissions ready.

 

Hey,
cleaned the MAF sensor
also threw a bottle of injector cleaner in the tank today,
will update you if there is any difference,
for now it's showing 8.2 MPG,

the fuel I'm running is 95 octane

 

My IS350 Sport is 10 years old going on 70K. The only issues it's had in 10 years is the infotainment system had to be refurbished a few year back (by the previous owner), dash replaced in January 2020 under the sticky dash extended warranty, and Shift Interlock Solenoid failed and had to be replaced. Pretty good for a 10 year old vehicle