vs1979

Hi,

I own Lexus GX 470 2007 with 94k on it. I have my car since 2009. Recently I noticed that I do not get the same mileage as I used to before (12-14 on the streets and 19-21 on the highway). All I get now is 8-10 on the streets and approximately 14-15 on the highway. I use the same gas station and use only premium gas.

In advise is appreciated

thank you

RCsGX

It could be winter gas. Most report loosing 1-3MPG. Other things to check / you may need:

• new spark plugs
• new intake air filter
• new air / fuel sensors
• clean the throttle body
• clean the MAF
• Check your tire pressure
• need new tires

vs1979

Thank you. I wonder how much it will cost to do all above.

RCsGX

Prices added. Of course add the cost of labor if you want a shop to do it.

You're approaching 100K so it wouldn't hurt to replace the spark plugs.
Change the air filter unless you've recently changed it.
You don't need air / fuel sensors. Most of the time you will get a code when they go bad but not always.
Take a look at the throttle body plate. All you have to do is remove the intake plastic elbow and if it's dirty clean it, if not leave it alone.
I would clean the MAF sensor just because. It's easy to remove and clean. Whatever you do, don't touch the tiny wire.
Check your tire pressure. Try to raise it 5PSI and see if it helps.
Only you know if you need new tires.

vs1979

Thank you for detailed response. Very helpful!

RCsGX

Not a problem. But more than likely it's the winter gas & colder temps. causing your drop.

MidniteGX

One more thing to consider is your drive-line fluids. This includes your front and rear differentials, your transaxle and your transmission. These all need to be changed on a regular basis and can affect mileage.

Upon recently changing my driveline (and engine) fluids to Amsoil products, I've noticed an improvement in gas mileage.

RCsGX

It's a good idea to change those too but I doubt that's the cause of a 4MPG decrease. I've swapped factory oils over to Amsoil on my last 4 vehicles and never noticed a difference in gas mileage.

OP you might want to check your calipers too. Toyota SUV / truck calipers are known for having stuck / sticking pistons. You might have one of more starting to stick and it's causing a slight drag...that can definitely cause you to loose MPGs quick!!

tecman

I am not sure what the difference is with winter gas, could you explain.

RCsGX

More butane:
http://itisscience.wordpress.com/201...-a-difference/

http://www.metrompg.com/posts/winter-mpg.htm

tecman

Thanks,I do not recall hearing this in Georgia, maybe it is not the case here due to climate and maybe state laws are different. I will look into it unless you know off hand. Thanks again for the info. I also wonder what difference it makes on performance.

shyguyF

My truck is right now about 15.5mpg in combination but i do not know with that number is bad or not, for sure it droped down a bit compared to the summer 17.5.

tecman

owned my GX for 6 or so months and always average 15.1 so your doing better than me. I also have duel exhaust so I would think I would be better but I admit I do like to leave everyone behind when the light turns green.

RCsGX

I noticed your sig. Do you also have a GX470?

If not the reason your 460 is getting a little worse on mileage is because it weights more than a 470.

StVeronus

Just picked up my 470 in Texas and drove it to SoCal. 1450 miles and averaged 16MPG (by fuel receipt/odo) and 16.1 by computer. Speed was probably (okay it WAS) the main reason for the lower numbers. I was doing 75-80 MPH most of the time. The truck is an 05 with 42K. Hope this helps.