I have a 99 GS300 with 139k that I just got a few weeks ago, I calculated my MPG over a few fill ups and i've been getting a steady 15MPG with mixed NYC city driving and highway driving id say about 50/50. Why are my MPG so low when I dont race the car I drive normal. Any suggestions anyone?

 

Which gas do you use? Maybe it's time to clean the Maf, throttle body, and replace the fuel filter.

 

Keep your foot out of it. Check you tire pressure and your air filter as well.

 

Don't feel bad. I get 16 mpg. 17 if I'm especially careful. This is stock engine too

 

NYC driving will use more gas than most folks do who lives out of town. even if they say they do alot of "city" driving their cities are not the same as nyc. I live here as well and noticed if i do mostly highway im lucky to hit 16-18mpg but if its strictly brooklyn & queens area driving 14-15 is the max if you put manhattan into it forget about it. we have WAY too much stop and go traffic! no matter what you do to the car its all the same unless you stay under 1500-2k at ALL times...

 

Are you using regular gas or premium? I go down to 15 mpg when I use regular, but goes up to 18-20 when I use premium. It can also make a difference if you are buying cheap gas over using a Top Tier gas supplier. Top Tier suppliers

 

Damn.. How heavy is your car? You got 4 15's in your trunk or somethin'? That seems super low. :/

2nd this. Also try some fuel injector cleaner & seafoaming. Make sure you keep up with how much air is in your tires. They could be low which will cause you to lose some MPG.

 

I ONLY use 93 from Sunoco or Shell, im very picky about what gas I use. Im the type to spent the extra money just for the Shell or Sunoco compared to Citgo which causes my grandfathers engine to blow up because the gas was watered down one time.

 

Fuel injector? which one do you recommend? and how do I check the air filter in this car? sorry lol im a lexus noob.

 

around how much does it cost to clean the MAF and throttle body and change the fuel injectors in this car?

 

i was gas mileage was at 11mpg city before a tune-up, now i'm at 16mpg city and about 20 highway..still pretty weak. it'll be much worse if you stuff the car with 5 heads.

 

thast about right i get 16 on my car and engine is stock too, and i dont gas it. seafoamed engine gas and changed sparks and all fluids. still 16

 

do you have stock rims on?

 

MAF cleaning and carb/throttle body cleaner will run you about $10-15, they are seperate cleaners. But doing that is pretty easy. In assume fuel injectors wouldn't be too difficult, but try running some fuel injector cleaner in your next tank and see how that goes.

 

buy Lucas for fuel injector cleaner man