keeping it in the family and traded my tc in for the new XB!:w00t:

I'll definetly miss the tc but I figure it was time to move onto something bigger and BETTER. I'm really loving the new xb w/ its unique styling. Got it equipped w/ fogs, trd muffler, 19" trd and a couple other parts. Spoiler and navi are going in tommorrow

Heres some pics I took after picking the car up





BUY ME! 4 sale at PREMIER TOYOTA OF AMHERST,OH

 

welcome to the other side...

 

whp makes those wheels??

 

Nice...another tC trade

 

Me too!!!!!!!!!!!!!!!

 

The wheels are Scion option 19 inch wheels.

 

Im itching. I love my 1st Gen....but at 2yrs its already got 56000 miles on it....Im looking, and thinkin about the 2nd gen.....

 

do they have the same wheels but in 17's cause 19's will effect the mpg?

 

I m currently 05 tC owner and trying sell my car. How much you guys get when you trade in with xB ? How much do you guys think I can get when I trade it in mine is 05 tC 24 K auto. Dont get me wrong I love my tC but I need 2 more extra doors so I am moving on to xB. =)

 

So you are saying that you don't want better gas mileage ? Because a larger diameter wheel / tire combination will have the "affect" of a gear ratio change that gets you better mileage.

I don't know if the height aspect of the 19" tires is the same as the stock tires, but it is probably not much of a difference.

 

Hope you enjoy your new ride! CONGRATS.

 

First of all, the TRD 19" setup has to be a VERY similar diameter to the stock tires, since it is dealer installed and they do not recalibrate the speedometer.

If they had a larger overall diameter, it would not necessarily translate to higher fuel economy. There is a point at which the diameter increase hurts mileage because the engine has to work harder to accelerate. This point varies based on the type of driving done. 100% highway and a taller tire is good for mileage. 100% city (as in, never above 35 mph) and a setup that is SMALLER than stock might INCREASE mileage. Ask anyone who has put big tires on their truck without changing the gearing. Mileage, AND acceleration, drop significantly.

Also, the TRD setup probably reduces mileage because they are heavier than the stock 16" steelies and because the wider, summer-oriented tread increases rolling resistance.

 

check kbb.com and thats what you'd probably get. Maybe a little bit more if you bargain w/ them.

 

just got the navi and spoiler installed today. Looks so much better and navi unit is awesome. Now all I have to do is bypass it

 

Well, you posted a lot of what if's, and maybe's and so on. Generally speaking as I was, in response to a kid with a Volkswagon and a Gen 1 Scion (Maybe, he has no pictures of that shown), he is not going to hurt his mileage with the 19" tires. The true biggest reason is that he probably is not going to buy 19's or 17's but even then if you read thru his posts you will see that he is younger and probably drives with his foot to the floor, so fuel economy is probably not a concern. I was trying to give him a little idea about this change, as it sounds from his post that he does not understand completely about what this change will do. I think the Gen 2 xB has enough power to overcome the tire diameter change, and as I mentioned in my post, the aspect ratio of the tire makes it a larger rim with a shorter tire and it comes out pretty much the same end result for overall diameter. It would be more salient to the discussion to measure the outer diameter of both than to speculate and post what if's in my opinion. Sure the tread design will affect mileage, but you could also say the same for if he drives on asphalt roads more than concrete, and if he drives a route that has more headwinds than tailwinds. He could also get better mileage by eating dinner after he drives home, so as to cut down on the total weigh he carries in the car, and he could keep the fuel tank below a 1/4 tank as to keep the weight down as well. More importantly, instead of worrying about the rim weight and tread design, would be to advise him to buy a good quality tire gauge and keep the tires inflated properly. That and avoid rapid starts and stops and he will be on his way to better mileage with whatever diameter tire he wants.
As far as the truck analogy, you also forgot to take in account what gear ratio was on the vehicle when you added the larger tires. On my F250 with a 4:10 ratio, I got better mileage, and a higher top end speed when I changed the tires to 38's, and of course the acceleration was slightly slower, but not much as we have not gotten into the discussion of torque vs horsepower and how it relates in a fixed time period to acceleration.

 

There is 1 "if".

Plain and simple he will get lower mileage in ALL conditions due to rolling resistance and weight. You can talk about pressures and how many tacos he eats, etc all you want; but the 19" setup will always lead to lower mileage in all situations. If I were to guess, I would say there would be a 1-3 mpg drop, again depending on where the car is driven.

I just checked scion.com, and the 19" setup comes with 235/35-19 tires. These are very very slightly SMALLER in diameter than the stock tires (0.2"). This would lead to a further change in mileage, although this effect would be basically immeasurable.

 

Interesting math you use.

For the 205/55/16 I get a diameter of 24.9 Inches
For the 235/35/19 I get a diameter of 25.5 Inches

I guess we should figure out what type of math you are using to come up with 25.5" being 0.2" smaller than 24.9" before we can have any meaningful discussion

 

I guess I was having a special moment, I put the wrong width in for the stock tire on the tire calculator site.

Interesting they would allow tire height to vary that much, the speedo will be reading nearly 2mph slow at 80 mph.

Regardless, mileage would go down unless you were on the highway pretty much all the time, and even then it would be unlikely that you would see a benefit. The taller tire would only lower the revs by less than 100, and that is not enough to overcome the increase in rotational inertia and rolling resistance.

Ohh, and I am sure it is just a typo, but the stock tires are 16, not 15.

 

Since we are all being so "accurate" (sorry could not help myself )
you can use the rims-n-tires calculator
http://www.rims-n-tires.com/rt_specs.jsp?postId=906
which shows:
so 18.8 revs per mile less.

This is the exact situation I have and my biggest concern is not the speed indication but the ability to accurately calculate gas mileage.

 

roXor boXor,

Did you happen to get a weight on your rims when you got them, or your tires? Sometimes, after market wheels weigh less than stock steel wheels as they are not solid and are made of aluminum usually, sometimes not though. That, and the weight of the tires is even more important, as the farther away from the center or hub of the wheel the weight is, the more effect is has on the equation.

Even more important to this discussion would be what your mileage results have been, since you have gone from the 16" to the 19" wheel. Since you have calculated your speedo as being off a percent or two at maximum, your mileage should also be pretty close. Please share with us what you have seen so far, inquiring minds want to know.

One other question / idea in regards to your mileage. Does the onboard trip computer keep track of the average speed cumulatively between fill up's / reset's ? Could you not use your average speed shown to calculate what your mileage should be, within a very close margin ?