rmbb1981

I bought an LS430 about 3 months ago. The car rides really well and I'm overall pleased. But the gas mileage is awful. I did a 7 hour highway trip this christmas. I got 24,5 MPG when doing 70 mph. In city traffic I'm getting between 10-13 MPG. This is a modern V8 from 2001, a small one at that. I can't believe it. My 1991 Lincoln Town Car and 1992 Cadillac Sedan Deville will consume less, much less actually. And those cars are generally considered gas guzzlers.

So, nice car but with this mileage, I don't know. I pay almost $8 a gallon in my country.

Jbthompson

I don't consider the 430 a gas guzzler, but its not an economy car in regards to fuel. City mileage depends on how you drive, quality of gas, temperature and the like. That seems a little low, but not outrageously so. I would recommend checking tires, cleaning the MAF sensor, throttle body, air filter, and replacing the plugs. With mixed city and high way driving, I am right at 19 right now. Thankfully gas is cheap now!

KING

iTrader: (1)

Cleaning MAF and throttle body will help. But it is no gas saver.

Don't forget to unplug the battery for half an hour. That will reset the ECU and hopefully provide you with a better MPG.

Jabberwock

I have a 2006 LS so it benefits from having 6 speed instead of 5 speed AT and I drive it very smooth and easy. My average long term mileage over the last few years for a mix of in town and highway miles is 21.4 based on car computer. Highway trips at 70 mph average about 26.7 mpg. I am really happy with the overall mpg, most 2001-2006 model year cars of similar size, power, and weight of the LS get lower mpg. Lexus did apprx 400 hrs of full size wind-tunnel testing on the LS430 to minimize drag and make it quiet. The SC430 of same model years gets lower mpg than the much bigger LS430.

Tom57

24.5 mpg @ 70 mph is actually quite good - especially for a 2001 V-8 heavy luxury sedan, and if you performed the maintenance items listed in post # 2, your city and highway mileage would increase. Start with correct air pressure in tires (around 34 - 35 psi - personal choice and depending upon tire specs), as rolling resistance can decrease gas mileage considerably.

Lavrishevo

iTrader: (1)

Just a correction, you don't need to disconnect the negative for 1/2 an hour to do a soft reset on the ecu. 30 seconds is plenty.

Is your air filter clean as well? Do you have a lead foot? In ideal running condition 14-18 mpg is about average city. City depends on your type of driving too. If you are in stop and go traffic a lot the mpg will fall drastically.

2KHarrier

I may be confused, but 8 dollars a gallon? Your location says Florida...?

polonius

I just got 27MPG on a 300 mile interstate trip last week in my 2005 LS430.

For the sake of your title line...I had a 71 Mercury Marquis with a 429 4V and never got much more than 15MPG in any conditions. Good thing it had a big tank...although the 22 gallons the LS holds does minimize the fueling stops. I don't think my sister's 73 Eldo 501 ever hit double digit MPGs.

Lavrishevo

iTrader: (1)

Not sure why he put FLA. He is in Sweden.

rmbb1981

I was living in Miami at the time. 33139

ancdmd

33139 here also!

AlexusAnja

There's a Florida in Sweden? I get 26 mph easily on highway and pure local about 12. If you're getting 10, either you have a lead foot, or quality of gas stinks. Using premium vs regular makes a difference too, but don't know if you want to pay $10/gal instead.

BradTank

Unless you're in some crazy congestion, something's wrong with your car.

Most of my driving is non-highway and I probably average between 19-22mpg.

Lavrishevo

iTrader: (1)

Only 26 mph on the highway! I would hate to get stuck behind you.

Anyway rmbb1981, what is your average speed and your tank average mpg via the computer? Mine is 33 mph and tank average of 21-22 mpg. I do about 70% highway / 30% city. Best mileage has always been on road trips on the highway of course. I have seen as high as 29 - 30 mpg under ideal conditions but it's usually about 25 - 27 mpg at 70 mph. The lower your average speed the lower the mileage is going to be, within reason of course.

AlexusAnja

darn right...that's how I get 35mpg... takes me forever to get anywhere...