Why would anyone want to play with the TCH's highly engineered systems, including the VDIM? Seems like another fantasy faith-based initiative to me.

 

I believe FE is Fuel Economy. Not sure how it comes into play here in this subject though..

 

I believe FE is Fuel Economy. Not sure how it comes into play here in this subject though

Several discussions in this thread:
1) Wider tires will hurt FE.
2) Heavier tire / wheel combos will hurt FE as well as handling and life of components
3) Spoilers may help or hurt the FE depending on the design.
4) Lowering the car could also affect the FE. Who knows? Toyota designed the underbody of this car to be aerodynamic as well. Lowering it could mess up the air flow. Typically it should help but in this specific case I'm not so sure.

 

I had failed to read all of the thread (sorry about that) when I made my post. I did realize what FE meant and posted it for information.

Certainly changing any of the parameters of the TCH may have an impact on FE. Maybe some positive - most likely negative or they would have already been done.

Increasing the inflation pressure of the tires will result in less rolling resistance. The reasons there is less rolling resistance are many but one thing to keep in mind is a reduced contact patch and thereby less traction. Be careful out there..

 

Wow, lots of random questions having nothing to do with my original post.

FE = fuel efficiency

Special Valve stems = the tire pressure monitoring system (TMPS) that your car came equipped with. If you don't move the TPMS sensors into your new wheels, then your car will constantly give you a warning regarding low pressure in your tires, because it is not receiving the signal from the tire sensors.

Your stock 16"x6.5" wheels have an offset of +45. So whatever wheel width you end up buying, you need to stay close to that relative offset.

The button does not "reset your pressure in your tires". It resets the TPMS system to accept the current pressure in your tires as the current calibration. See this recent thread for instructions on how to do this:
https://www.greenhybrid.com/discuss/...ing.10091.html

 

I finally found an affordable set of Lexus GS430 18" wheels to put on my TCH, they are on the way and should be mounted up in the next couple of weeks, so the next decision is whether or not I want to install the TRD springs. Here is a nice thread from ToyotaNation that shows what a 07Camry looks like with 18's and the TRD springs.

http://www.toyotanation.com/forum/sh...d.php?t=159666

 

Finally got my TRD lowering springs in this weekend... what a difference!

New car pics will come after the weather clears up here in Houston... flooding and big storm here last two days. But it does look exactly like my photoshop exercise a while back...

Before:


After:


The lowering aspect is probably for cosmetics as much as anything... just gets rid of some gap above the tire. What is very cool is the ride improvement due to the springs being progressive rate! No more "waterbed" effect over dips in the road. The first part of the suspension movement is nearly identical to stock in feel. It's just that further movement is resisted by the spring... a more sports sedan feel. No, your car won't be passing BMWs up that mountain canyon drive but it WILL be a lot more fun to drive. Who says hybrids have to be mainstream stock in handling? Maybe some of us want an SE Hybrid!

Some of my handling is also due to a change to 17" Avalon Touring rims and their 215/55-17 tires. Using 18's and 45 series tires will move you more up the firm ride direction. It's just too bad that TCHs with all the various combos aren't available to test drive... you are on your own and better keep the olds parts after each mod so you can go back if needed.

If you don't have a Factory Shop manual get one off eBay for the car... strut swap part is well detailed. The install for all four took me about 4 hours using my pretty complete shop with air tools etc. If not an advanced DIYer I'd farm out the job to a shop. If you aren't comfortable with your front end alignment afterward then that's another item.

Here is the stock and TRD rear spring compared:



The big question is how much will it lower? My front wheel well lip to ground measurement went down 1 1/4 inch both sides. But the back was down 1 3/4 inches. Looked a little tail dragging. This matches what Eibach Spring (makes these for TRD) said about the TCH not being a tested application (CE, SE, LE and XLE are OK) for these parts when I called their R&D about them. They FIT but the hybrid having an extra 200 lbs+ battery in the back drops you down. Ideal would be another rear spring specific for TCH. For the not so faint of heart there is a work around. The top of the rear strut mounts with three studs that go into the body behind the back seat. They are over 1" long but don't need to be... just enough to catch a nut. I made spacers of 3/4" stock the same shape as the strut mount and put them between the body and strut. You get back exactly 3/4" and rear drop is now 1" just like the front. I'm checking into a limited run of these in aluminum via cnc machining -- till then you are on your own.

For those who make it this far reading what is being shared in the interest of group brain for those who want to modify their cars... thanks! And thanks in advance for also refraining from posting your lecture about modifications to TCHs. Just gently close this thread and back sloooowly away .

 

Uhm, I see NO difference between the two pictures. Even the shadows are identical.

 

Thanks for being the guinea pig!


So some of the things you've said have scared me a little, especially since I do not have a shop where I can install springs myself or fabricate any parts, so I'm going to wait a while longer before I go for this mod on my TCH. First off, in order to counteract the speedo error, I'm ordering slightly larger tires 235/50-18 to go on my 18" wheels. Your tire upgrade was only a 0.6% increase in outside diameter, but my upgrade will be a 4.2% increase in outside diameter than the stock 215/60-16, so my speedo should now read more accurately, although my odometer and FE-meter is going to be completely screwed up. But since I will already be using larger tires filling up the wheel wells, I am very afraid that with your "larger than expected" drop in the rear with the TRD springs, the tires might end up rubbing. So I think I'll mount the new tires and see how that looks. If I still think I need lowering springs to achieve the look I want, I might wait until TCH-specific springs are produced.

Post some close-up profile pics!

 

And you'll extend your base 3yr/36k warranty by 1,512 miles. Unless Toyota wises up and takes yours bigger skins into consideration. I wonder if that could be considered tampering with the speedometer?
Just thinking out loud.