Why is my mpg so bad?
#1
Lexus Test Driver
Thread Starter
Why is my mpg so bad?
I have a 2002 sc430, around 108k miles. My car is meticulously maintained. I have new plugs, a clean air filter and injectors, and I use premium synthetic oil. My trip computer indicates that I get about 13 mpg in dense city traffic. How could this be? Could I be missing an important maintenance item?
#3
In dense city traffic that may be the norm.
Look at my fuel tracking https://www.fuelly.com/driver/flyct/sc430
My best with 30% city driving is 23.9 MPG
My worst with 50% city driving is 17.6 MPG
My city driving is not normally in dense city traffic. When i occationally find myself In downtown, stop and go dense city traffic I see 13 MPG immediately after fill ups. Once I get out of dense traffic it gets better.
I'm pretty light footed unless I'm entering a highway entrance ramp where I love to floor it until reaching 75 MPH to burn out the carbon.
My highway driving is at 72 MPH in cruise for 200 miles without stopping.
JR
Look at my fuel tracking https://www.fuelly.com/driver/flyct/sc430
My best with 30% city driving is 23.9 MPG
My worst with 50% city driving is 17.6 MPG
My city driving is not normally in dense city traffic. When i occationally find myself In downtown, stop and go dense city traffic I see 13 MPG immediately after fill ups. Once I get out of dense traffic it gets better.
I'm pretty light footed unless I'm entering a highway entrance ramp where I love to floor it until reaching 75 MPH to burn out the carbon.
My highway driving is at 72 MPH in cruise for 200 miles without stopping.
JR
#4
Lexus Test Driver
Thread Starter
In dense city traffic that may be the norm.
Look at my fuel tracking https://www.fuelly.com/driver/flyct/sc430
My best with 30% city driving is 23.9 MPG
My worst with 50% city driving is 17.6 MPG
My city driving is not normally in dense city traffic. When i occationally find myself In downtown, stop and go dense city traffic I see 13 MPG immediately after fill ups. Once I get out of dense traffic it gets better.
I'm pretty light footed unless I'm entering a highway entrance ramp where I love to floor it until reaching 75 MPH to burn out the carbon.
My highway driving is at 72 MPH in cruise for 200 miles without stopping.
JR
Look at my fuel tracking https://www.fuelly.com/driver/flyct/sc430
My best with 30% city driving is 23.9 MPG
My worst with 50% city driving is 17.6 MPG
My city driving is not normally in dense city traffic. When i occationally find myself In downtown, stop and go dense city traffic I see 13 MPG immediately after fill ups. Once I get out of dense traffic it gets better.
I'm pretty light footed unless I'm entering a highway entrance ramp where I love to floor it until reaching 75 MPH to burn out the carbon.
My highway driving is at 72 MPH in cruise for 200 miles without stopping.
JR
#5
Go to www.fuelly.com Register for free, after filling up you just enter odometer reading, gallons added, price per gallon and % city driving. The site calculates, tracks and graphs everything for you.
Entering takes a minute at the pump.
You can see my 4 cars here; https://www.fuelly.com/driver/flyct/
Click on any of the cars and see the details.
JR
#8
Yes, this could be a contributing factor. The piggyback ECU sends preprogrammed fuel/ignition maps to the engine ECU and I believe Moe was conservative in regards to the maps. So I'm sure you're running a little rich, but I prefer that buffer instead of leaning out the engine especially at the higher rpms when our intake manifolds open up.
When I had it on my GS400, I got 19mpg around the city and that hotdoggin' it around corners . I have the injen on the SC and I'm getting about 21 mixed (70% in the city).
When I had it on my GS400, I got 19mpg around the city and that hotdoggin' it around corners . I have the injen on the SC and I'm getting about 21 mixed (70% in the city).