dliugear

Hey guys, I'm very proud as a GX owner,
However, as the gas price booming up.
Maybe it is the time that we change the spark plugs?
Idk what spark plug Lexus put it the engine,
does it still have the potential to be improved? say better mpg ? more HP ?

any thoughts?

redrocks

What's your current mpg? Is it within the EPA estimates?

ROK

unless those spark plugs can somehow magically shave about half a ton off your GX, it won't make any real diff in the wallet.

Ancient

I hear you about the higher gas prices. With regard to spark plugs. If you engine is running smooth and you are not at the mileage to change them, save your money. No magic bullet.

You can increase mileage by:

1. Make sure your tires are up to proper pressure. Increasing a pound or two above recommened pressure. This is the most significant improvement you can make. Larger tires will ding you a little.
2. Clean air filter
3. Keep your windows rolled up and don't run the air conditioner, unless necessary.
4. Buying gas without alcohol. In Iowa, probably don't have that choice.
5. Others have recommended injector cleaner additive every now and then. You would have to do a search.
6. Take an unecessary weight out of the vehicle. I never use the third row seats, took them out.

On a good day, flat freeway, no high wind, I can get 20 mpg ( 2008 GX), but I drive like I have an egg on top of the brake and gas pedal. No stomping on either pedal.

dliugear

20 mpg... That was the dream.
After I put on 20' , I've only got around 15 on freeway. Tire pressure are correct. Air filter replaced by K&N
The list number 4 just blind my freakin eyes..before u pointing it out, I thought all the states has this ethanol gas...WTF..

Matsui

Can ethanol based gasoline cause any harm to our cars?

I just had an ignition coil replaced on another car which is a 2011 with only 20k miles. I always put 93 in all my cars, but I think using ethanol based gasoline that some gas stations offer could have been the culprit.

masboy

iTrader: (30)

just changed my spark plugs few weeks ago ( 130K miles on it ), i gotta say, i feel the difference on responsive. when I hit the gas pedal, the car is more responsive than before. mpg hmmm can't really tell, ive been getting 17-18 mpg.

golfdawg

I wish to God I knew how any of you get that type of mileage. On a GREAT day I will get 16......never have I seen anything over that. What am I missing. Yes to all the questions. Proper inflation, clean filters, drive easy, yada yada yada....................

clubsport

i have a g35 coupe too that people on other forum always stress as being important that you should change spark plugs to increase performance ie hp output at the wheels, thus would increase mileage from better combustion - so i guess if you're over 100k miles then those plugs need a changin

dliugear

Do u wanna share which spark plug u choose?

dliugear

I actually have a tip, my previous ride is a BMW 335, and I really like to hit the brake at the very last moment.
After I switch to gx, I found the distance this big truck can continue moving without stepping on gas is amazing, maybe it's because the huge weight of it can give u more inertia.

Right now from signal to signal, I feel like saving 30% gas by stepping on gas less.

If u'r talking about freeway mpg, what's ur usually speed?
When I still using the stock rim and tire,
My mpg is 19 around 70
18 around 80
16 around 85'

Righ now, is constant 15.
And, btw MPG doesn't matter to what gas u use.

Ancient

dliulgear My 20 mpg average, was only freeway for me, which is fairly flat, and at a boring 67 mph. So you are only (1) mpg less. Seems the newer GX models get about a mpg more than lets say an 04. Just like the new generation GX seems to hit 20 mpg, more often.

Don't know if Ethanol hurts an engine. I do know that most new cars can detect it and adjust for it. I seem to get less mpg. Like Rox says, unless you take a ton of these beasts, mileage isn't going to change much.

I did have a Hemi a few years ago and took it into the dealer at 60K to have the plugs changed. The service manager ask me how it was running and was I suffering an noticeable loss in mpg. NO, was my answer. He said, don't change them yet. If you can change them yourself, it isn't much of an expense.

ALAN553

i used the stock NGK iridium, changed them at 90,000 now have 120k on them.

cdew002

Yes, ethanol is bad for all 1st gen GXers -

http://www.popularmechanics.com/cars/alternative-fuel/biofuels/e15-gasoline-damage-engine