Yes.

The 18s are heavier, both the wheels (bigger diameter) and tires (wider). Especially rotational weight, it takes more power to rotate the wheel/tire, making the car less efficient. Making it use more gas and making the car slower. So actually the LS430 with the 16's is the quickest and most fuel efficient.

 

Go find and read the MPG thread, guys running 16s/17s are getting 25~28 MPG, guys with 20s are getting 18~20 MPG.

I forgot to mention, the wider tires from the 18s increases the rolling resistance also, which decreases MPG.

 

Just curious BNR34, are you saying that with 18's your fuel economy is going to go down from 17's?? If so why?[/QUOTE]

I believe the OEM 18's, you'll be going from 225 to 235 (or 245) wide tires, so that alone will cause you increase road resistence/friction and lose MPG. Better for handling yes, but not for just plain rolling. I think you'll lose maybe 2 mpg tops, but more likely 1 mpg.

If handling is what you're looking for, going to 18 will help. If you like the 17, then just keep them. I have 17 for snow tires and 18 for summer, only because my LS came with the 17 and I didn't wan't to switch tires back and forth between seasons. Got 18 because I like them...

 

I'll be damned...I never knew that. I did know about a wider footprint causing more resistance but not about the rotational weight. Thanks for the info.

 

i asked the previous owner about the air shocks- and he said they had never been replaced. So... for some odd reason (relative to what you guys have said) I have 240k on my air shocks. Seems like a lot, makes me happy (unless they go out soon )

 

No problem.

It is one factor why economy cars with tiny 14"-16" wheels with skinny tires gets better MPG. Look at all the cars that focus on fuel economy, all the Hybrids or cheaper economy cars, they all got small wheels with skinny tires.

 

wow, that is hard to believe. I appreciate you checking for me though