Horrible MPG
Both the GS300 and the GS400 uses the same transmission. However, the final drive is different. The GS400 uses the 3.26 ratio while the GS300 uses the 3.92.
Where the GS300 saves gas by having less cylinders, the GS4 saves gas by turning at a lower rev.
Where the GS300 saves gas by having less cylinders, the GS4 saves gas by turning at a lower rev.
Thread Starter
Lexus Test Driver
Joined: Jan 2007
Posts: 1,054
Likes: 1
From: Dirty Jersey
Are you putting in premium gas? GS' should not be run on regular. Like he said, if it only took $46.00 to fill up, I suspected you are only buying 87 octane or not filling up completely. If you're using 87, you're car is not going to run as smooth and you'll get less mileage. It cost me $58.00 to fill up w/ premium this week when my tank was bone dry.
Well check this out.
Figuring gas at $3.25 a gallon, you are putting in 14.15 gallons for $46. You are getting 275mi from 14.15 gallons which equates to 19.43 miles per gallon mixed highway/city. Honestly I think thats exactly where it should be. I mean, I did an all highway trip averaging in the 60mph range for about 1000 miles. I got 23.5 mpg on the trip using premium gas (which I assume your using as well). So you seem like you are right in range with where you should be
Btw- Take this into account, if you are in the city and sitting in traffic (more sitting than just the average stop and go) you are just burning fuel while being basically stopped, that will eat way into your mpg.
Figuring gas at $3.25 a gallon, you are putting in 14.15 gallons for $46. You are getting 275mi from 14.15 gallons which equates to 19.43 miles per gallon mixed highway/city. Honestly I think thats exactly where it should be. I mean, I did an all highway trip averaging in the 60mph range for about 1000 miles. I got 23.5 mpg on the trip using premium gas (which I assume your using as well). So you seem like you are right in range with where you should be
Btw- Take this into account, if you are in the city and sitting in traffic (more sitting than just the average stop and go) you are just burning fuel while being basically stopped, that will eat way into your mpg.
Using the breakdown above if it's only costing you $3.06 a gallon that means you are putting in 15.03 gallons. That drops you down to 18.3mpg mixed...still not too bad I don't think. Are you doing alot of really slow stuff, like sitting in rush hour traffic? If so thats really going to put a hurt on your mileage. "City" is meant more like stop and go, not like stop-stop-stop-go know what I mean?
Last edited by macd7919; May 8, 2007 at 12:03 AM.
I would recommend using a gas treatment for the next couple of times you fill up. I have a 430 and I'm getting about 325-350 a tank. I use STP gas treatment often, sometimes every other fill up.
Lead Lap
Joined: Oct 2006
Posts: 474
Likes: 0
From: Brooklyn, NY
I'm in the sam boat as rayy...but I have the 400. I still get only 250 miles out of my tank! I'm doing probably 70/30 city/highway driving. I don't understand, I clean my K & N filter (FIPK Intake) every 3-4 months, I cleaned my throttle body 5 months ago, I got a fuel injector service at the dealership about 4 monthsd ago, and I put about 3 Techron fuel system cleaners within the last 4 months time. What's the deal??? Even when I drive like a grandma I still don't get anymore tha 260 miles and the needle is slightly below "E." I don't know what else to do...can it be my torque master plugs??? And what about this fuel filter? I keep hearing everyone say that it NEVER needs to be replaced and it doesn't get cleaned manually - sounds weird to me. For all I know I could have a major blockage in there. Help guys, tell me what's the deal...
Lead Lap
Joined: Dec 2005
Posts: 661
Likes: 2
From: GRAND RAPIDS, MI
I'm in the sam boat as rayy...but I have the 400. I still get only 250 miles out of my tank! I'm doing probably 70/30 city/highway driving. I don't understand, I clean my K & N filter (FIPK Intake) every 3-4 months, I cleaned my throttle body 5 months ago, I got a fuel injector service at the dealership about 4 monthsd ago, and I put about 3 Techron fuel system cleaners within the last 4 months time. What's the deal??? Even when I drive like a grandma I still don't get anymore tha 260 miles and the needle is slightly below "E." I don't know what else to do...can it be my torque master plugs??? And what about this fuel filter? I keep hearing everyone say that it NEVER needs to be replaced and it doesn't get cleaned manually - sounds weird to me. For all I know I could have a major blockage in there. Help guys, tell me what's the deal...
Wow, I'm surprised you're not getting much better because I've done all the same things as you. I consistantly get at least 320-330 miles every tank. I've even got 350 before with more than average highway driving. Thats with the power button on about half the time.
only run 93 octane
1998 GS400 w/104k 12-14k per year
cleaned throttle body & MAF
K&N filter - clean it about 8-10 months
fuel injector cleaner - around every 6000 miles
18" rims- not sure on weight but they're not too light
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Nick, it's probably the way we drive in the city, my mpg SUXS (anywhere from 10-14mpg) in the city, I thought it was a problem and was getting ready to put the car in the shop. But this weekend on the trip to Carlisle I averaged 22.9mpg on the highway and considering I had a passenger, my 19's and new sub in the trunk along with other gear it makes me believe that I'm the one that needs to change, not the car.
