2003 Gs300 Gas Milage As Bad As Hummer!

[danyeru]

I first want to start off and say if this is posted somewhere, I am sorry for reposting this question. The site would not let me search.

This said,

I recently purchased a used 2003 GS300 with 42,000 miles on it. I have been averaging 14.9 mpg - 16.9mpg. This is with 60% driving city and 40% highway. The EPA suggests 18mpg city and 25 highway. I should be averaging around 20mpg. I took my car into the Lexus Dealership where I purchased it, and they kept it for 2 days, testing it on the machines, and supposedly filled it up, drove 41 miles, and put 2 gallons back in it. Therefore getting 20.5 mpg.

During this time they loaned me a ES350 (EPA 21 city 30 highway) which I have been driving twice as aggresive as I do my own. I have been driving it 75% non aggresive but 25% aggresively flooring it, and accelerating harder than in my own and I am averaging 21.5 mpg. HOW the hell does this happen?

I traded in a 2006 350Z which has 19city and 26 highway. I drover car the same 60% city 40% highway and averaged 21-24 mpg when driving non aggressive, and 18-20mpg when driving more aggresively. When I drove it completely messing around, power sliding, racing, highway speeds at 90+ I would STILL GET 17mpg, Which is MUCH better than the GS300 getting 14.9mpg when I am driving barely aggresive. (before anyone says anything about my racing, power sliding, and 90+ highway speeds, understand this is this reason I got rid of the 350Z and got the GS300)

Has anyone else had this same issue? or Should i just accept getting crap for gas milage?

[raymsixsix]

I think thats about right. I had an 01 GS300 and if I drove it easily in the city I would get 17-18 mpg. On the interstate with cruise control set at 80 I would get 26-27 mpg. If I drove it with a lead foot, the gas mileage would dip dramatically. The EPA estimates are a joke, you have to remember that those figures are attained in ideal driving situations/environments.

[AstonM]

My 2000 GS300 @ 91K miles gets around 16 to 19 mpg at mostly non aggresive city driving, I don't drive it nearly as hard as my old 92 camry V6 I had before this, which still got just a little better mileage.

I'v had it for only a month and i'm still doing mileage testing on it.

[danyeru]

I think thats about right. I had an 01 GS300 and if I drove it easily in the city I would get 17-18 mpg. On the interstate with cruise control set at 80 I would get 26-27 mpg. If I drove it with a lead foot, the gas mileage would dip dramatically. The EPA estimates are a joke, you have to remember that those figures are attained in ideal driving situations/environments.

I would love to be getting those kinds of averages. I just drove 30 miles after getting it back and went and topped it off. I put in 1.502 gallons..... so i pretty much got 20mpg... Let see what happens when i drive 150 miles.

I dont mind that the estimates are a joke, which Lexus said they are bs... but every car i have ever driven has gotten better than the city, usually inbetween the two numbers. Like i said before the 350z averaged 20-24 in 40% highway 60% city driving. My 97 civic didnt start getting below the city average until 150k+ miles

[qpdo]

I know its a differnt generation GS300 but my '91 Aristo gets about 22-24MPG cruising on the highways... still not entirely sure how well it will do in the city.

qpdo

[johnsonhuang]

thats not toooo shabby. on my G, i get about 10-12 mpg... when gas prices were 3.89 per gallon, it left a nice little dent in my pockets.

[djspawn00]

I gauge my mileage after every tank. I usually refill somewhere around 250-275miles averaging between 17-19mpg with mostly highway driving. I was getting between 14-16mpg at one point and that was due to an O2 sensor that was on its way out. other than that, no complaints, if i couldn't afford that gas then it would be my fault, why get a lexus when you can get a corolla is your mileage is your primary concern.

[1999Lexus_GS400]

Wow those numbers so low for a GS300 6 cylinder, I thought they would do better be a smaller engine. My GS400 get 400 plus miles to a tank on the highway, at 65-70 mph. I think in the city it considerably less because I drive more aggressive.

Just my 2 cents....

Dave

[lexuseng]

Our 2001 GS300 which my wife drives 15 miles to work and fills up about every 10 days. We average about 21 mph, easy over 300miles every fill up. She's not a lead foot but she doesn't drive like an old lady either. On a trip from Seattle to Spokane (up and down a pass plus a lot of flat) we got 23.7.

[JRRRRRR]

I first want to start off and say if this is posted somewhere, I am sorry for reposting this question. The site would not let me search.

This said,

I recently purchased a used 2003 GS300 with 42,000 miles on it. I have been averaging 14.9 mpg - 16.9mpg. This is with 60% driving city and 40% highway. The EPA suggests 18mpg city and 25 highway. I should be averaging around 20mpg. I took my car into the Lexus Dealership where I purchased it, and they kept it for 2 days, testing it on the machines, and supposedly filled it up, drove 41 miles, and put 2 gallons back in it. Therefore getting 20.5 mpg.

During this time they loaned me a ES350 (EPA 21 city 30 highway) which I have been driving twice as aggresive as I do my own. I have been driving it 75% non aggresive but 25% aggresively flooring it, and accelerating harder than in my own and I am averaging 21.5 mpg. HOW the hell does this happen?

II traded in a 2006 350Z which has 19city and 26 highway. I drover car the same 60% city 40% highway and averaged 21-24 mpg when driving non aggressive, and 18-20mpg when driving more aggresively. When I drove it completely messing around, power sliding, racing, highway speeds at 90+ I would STILL GET 17mpg, Which is MUCH better than the GS300 getting 14.9mpg when I am driving barely aggresive. (before anyone says anything about my racing, power sliding, and 90+ highway speeds, understand this is this reason I got rid of the 350Z and got the GS300)

Has anyone else had this same issue? or Should i just accept getting crap for gas milage?

My '04 GS300 has 35,000 miles on it. I may drive more conservatively than you wife (i.e., 70 mph w/cruise set, etc.). I drive it from Seattle to Montana twice a month and I'm averaging 30 mpg! Even in and around town it's getting 25 to 27 mpg.

[BrostyDawg]

I first want to start off and say if this is posted somewhere, I am sorry for reposting this question. The site would not let me search.

This said,

I recently purchased a used 2003 GS300 with 42,000 miles on it. I have been averaging 14.9 mpg - 16.9mpg. This is with 60% driving city and 40% highway. The EPA suggests 18mpg city and 25 highway. I should be averaging around 20mpg. I took my car into the Lexus Dealership where I purchased it, and they kept it for 2 days, testing it on the machines, and supposedly filled it up, drove 41 miles, and put 2 gallons back in it. Therefore getting 20.5 mpg.

During this time they loaned me a ES350 (EPA 21 city 30 highway) which I have been driving twice as aggresive as I do my own. I have been driving it 75% non aggresive but 25% aggresively flooring it, and accelerating harder than in my own and I am averaging 21.5 mpg. HOW the hell does this happen?

I traded in a 2006 350Z which has 19city and 26 highway. I drover car the same 60% city 40% highway and averaged 21-24 mpg when driving non aggressive, and 18-20mpg when driving more aggresively. When I drove it completely messing around, power sliding, racing, highway speeds at 90+ I would STILL GET 17mpg, Which is MUCH better than the GS300 getting 14.9mpg when I am driving barely aggresive. (before anyone says anything about my racing, power sliding, and 90+ highway speeds, understand this is this reason I got rid of the 350Z and got the GS300)

Has anyone else had this same issue? or Should i just accept getting crap for gas milage?

I have a 2003 GS 300 sport design and I average in the city 24 and Highway 28. I seen a big jump when I switched over to a synthetic oil and a K&N AIR filter.

[smooth1]

One of the issues with safe tuning from the factory is what you are experiencing here. Toyota allways tunes a little too rich on the A/F mix. Which alone causes a little lower gas mileage. But it also clogs up and dirties the 02 sensors faster. Which as they get dirty, don't read as well, and tell the ECU to make it even richer. I can pretty much go to the exhaust, let someone start it, and smell the fuel in the exhaust coming out.

The reason Brostydog saw an increase in fuel mileage was because he increased the air flow which is probably offsetting the fuel mixture. ( Although I have to admit that his results seems on the high side.)

Make sure all your 02 sensors are working properly. As a bad sensor can be sending the wrong info to the ECU. If they all work then, after taking out your 02 sensors, clean them with wd 40 and then electronic parts cleaner. ( It removes all the residues.) then put them back in. Then unplug the negative battery terminal for about a half an hour. (that will reset the ECU.) You should see a nice improvement in fuel mileage.

One other thing to remember, is that the ECU "learns" your driving habits. So, what you may feel to be "easy" driving in one area, may be offset by a habit somewhere else in how you drive. In which case, an ECU reset will help out with again as it restores all the settings back to factory.

[99blkgs]

One of the issues with safe tuning from the factory is what you are experiencing here. Toyota allways tunes a little too rich on the A/F mix. Which alone causes a little lower gas mileage. But it also clogs up and dirties the 02 sensors faster. Which as they get dirty, don't read as well, and tell the ECU to make it even richer. I can pretty much go to the exhaust, let someone start it, and smell the fuel in the exhaust coming out.

The reason Brostydog saw an increase in fuel mileage was because he increased the air flow which is probably offsetting the fuel mixture. ( Although I have to admit that his results seems on the high side.)

Make sure all your 02 sensors are working properly. As a bad sensor can be sending the wrong info to the ECU. If they all work then, after taking out your 02 sensors, clean them with wd 40 and then electronic parts cleaner. ( It removes all the residues.) then put them back in. Then unplug the negative battery terminal for about a half an hour. (that will reset the ECU.) You should see a nice improvement in fuel mileage.

One other thing to remember, is that the ECU "learns" your driving habits. So, what you may feel to be "easy" driving in one area, may be offset by a habit somewhere else in how you drive. In which case, an ECU reset will help out with again as it restores all the settings back to factory.

hey smooth one i got 2 99 gs 300's and they both smell like gasoline when you start them off so im guessing i should take out and clean them in both vehicles and can i just buy electronics parts cleaner at my local auto zone or pep boys?? thanks