Had my 2000 GS300 for about a month. Lowered on 20-inch wheels. Only performance mods are intake and exhaust. City driving with some incline hills I get about 220-240 miles from full tank using Shell premium gasoline. I'm a cruiser because I'm lowered and don't really go past 3500 rpm on the tach, dont have heavy foot. Does this seem right to be only getting that much miles? Thank You

 

Already tried cleaning throttle body, maf sensor, and changing spark plugs to ngk iridium.

 

I have headers and downpipe with a kn drop in without a tune and I get 29mpg. also what are you cruising at because i cruise at 75 mph and at 2800rpm or so even at 80 i'm under 3200rpm. use a can of seafoam to see if your injectors need cleaning since you did the other things. and to answer your question, no that doesn't seem right as I've cruised over 400 miles on a single tank on the highway. while i think the 20s may decrease your fuel mileage i don't think it would be by that much. get a cheap obd2 bluetooth reader off ebay and download Torque Pro on your phone.

 

the app let's you record random parameters and see how your car is performing in real time. and has obd protocols so it can read/erase codes. good for diagnostics and general info on performance

 

You've got big heavy wheels and a lot of city driving in a heavy luxury car, which doesn't bode well for gas mileage. Combine that with a winter fuel mixture and you're not going to be doing too well. I wouldn't be too surprised by low gas mileage.

 

nezlyfe, there's no way your car is getting 29mpg lol. The best I have ever seen a GS300 get is around 24mpg, and that's with cruise control set at 70mph on a road trip.

If you do the math...
The gas light comes on in these cars usually when the tank has 3 gal left in it. The tank is a 19.8gal. So when the gas light comes on, you have used roughly 17gal.

17gal @ 24mpg = 408mi

If you claimed to get 29mpg, that would mean you can go 493mi until the gas light comes on.

In most cases GS300 will average about 21mpg mixed city/highway in most cases.

My hybrid GS450h barely manages to get 29mpg lol, so I find it hard to believe the older 2JZ GS300 can do the same 29mpg.