grabber2

I'm getting 15.1~15.4MPG now with 82K, I will change my plugs & see if it gets any better in MPG

mandyfig

I will go for OEM specified plugs. Just looked at the manual:

Denso SK20R11

NGK IFR6A11

Pearlpower

iTrader: (2)

I would avoid any of cheaper brand plugs as well as stay way from those Pulstar plugs due to quality concerns. Iridiums are a perfect choice and nothing wrong with changing plugs early.

mandyfig

Are the OEM plugs Iridium?

mandyfig

Also as I read in the manual, all we need to do is remove the V bank cover and the air intake and oil stick.

All 8 coils will be visible and accessible.

Remove coils (number them so they go back home), remove spark plugs. Drop new ones, torque right, re-install coils, torque properly and re-install Air intake and V bank cover. Done?

mandyfig

Did some research, the OE plugs are Iridium. Here are the Part numbers:

NGK 4589 Laser Iridium This is original IFR6A11
3764 Alternate, Iridium IX BKR6EIX-11

Denso 3297 Iridium Longlife, This is original SK20R11
5304 Iridium, alternate IK20

I am looking at the NGK 4589's myself.

tentoys

I've changed the plugs twice in my 99LC in 155K miles and never noticed any difference in performance or mileage... just peace of mind. Used platinum once and iridiums the next time. Went to the iridiums for the longevity as it is such a PITA.

mandyfig

How is it a PITA? What's the hardest portion?

tentoys

I was referring to a Land Cruiser rather than my wife's SC just to suggest that early intervals may have been a waste of time and money. just being "old school" about tune-ups i was leery of going 90-100K. However, it seems that going ahead of interval made no discernible difference.

Poqman

I agree with that. I was amazed how good the old plugs looked at 96k miles. I was getting 18.6 mpg before and 19.2 after replacing the plugs. What improved my mileage the most was cleaning the MAS sensor and throttle body. My mileage had dropped to 16 and jumped back to 18.6 after cleaning. Idle smoothness improved too. Didn't notice a change in smoothness when I replaced the plugs.

bagyo

Torque Master spark plugs seem to be the way to go, especially for Lexus OEM quality aficionados. i swapped them into my ES and LS and have noticed a slight difference in mpg, performance and how smooth the engine runs. Well worth the extra green . Look it up at Lexus L-tuned, l-tunedparts.com

UnSub

The IK20 is what my Tundra lists. Because it is supercharged, I went one range colder and got the IK22. I have over 30,000 miles on them with no problems. It is almost time to change them again so I will pull one to see what it looks like. I can't honestly say if the truck ran any better on these plugs. I can say there was no increase in mpg.

iolmaster

iTrader: (1)

Unless you have a bad plug, plugs don't make engines run smoother or add performance. The only purpose of the plug is to ignite the fuel air mixture. If it does that it works. But I guess perception is reality.