Downsizing from 205mm & 16" to 195 & 15" wheels/tires worth it? - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

MPGee · 10-05-2016, 09:14 PM

Quote:

Originally Posted by MPGeo

11lbs is a very good weight for factory 14"

... I'm pleasantly surprised.

That's a nice user-name you've got there.

vskid3 · 10-05-2016, 11:17 PM

Quote:

Originally Posted by MPGee

Cool! Aardvarcus, what was your last ride? And do you recall which year Prius those wheels came from, and maybe how much the weight was before/after?

Probably a Gen3 (2010-2016) if they were black alloys. Here's a site I found that lists the wheel specs for a lot of cars, here's for your car Toyota Matrix 2007 - Wheel & Tire Sizes, PCD, Offset and Rims specs - Wheel-Size.com and 2010 Prius Toyota Prius 2010 - Wheel & Tire Sizes, PCD, Offset and Rims specs - Wheel-Size.com There's also a list of cars that have the same bolt pattern 5x100 - Bolt pattern - Wheel-Size.com I've been looking to get another set of wheels for snow tires for my Prius, so I had most of these links already open.

oil pan 4 · 10-06-2016, 10:06 AM

On my wife's car I went from the stock 215/55r17 to 215/60r17 and that larger size it turns out is more common and $20 a tire cheaper.
Also why are you not trying to go taller?

aardvarcus · 10-06-2016, 12:24 PM

Quote:

Originally Posted by MPGee

Cool! Aardvarcus, what was your last ride? And do you recall which year Prius those wheels came from, and maybe how much the weight was before/after?

MPGee,

Vskid3 was correct they were stock wheels from a 2010+ Prius. My old car was a 2002 Toyota Celica. The 16" stock alloys I removed were around 21 lbs, and the 15" prius wheels were around 14 lbs. The tires were lighter too, I don't remember the specifics on those. That wheel and tire combo is still going strong on my brother in law's car, as I swapped on some other less valuable wheels and tires prior to selling.

MPGee · 10-06-2016, 05:30 PM

Quote:

Originally Posted by oil pan 4

On my wife's car I went from the stock 215/55r17 to 215/60r17 and that larger size it turns out is more common and $20 a tire cheaper.
Also why are you not trying to go taller?

I assume you're asking me? I'm not trying to go taller (as in larger overall wheel+tire diameter), because I'd like my speedo & odo to remain accurate... Otherwise, how am I gonna know if I've actually improved my fuel economy?

MPGee · 10-06-2016, 05:47 PM

Quote:

Originally Posted by aardvarcus

MPGee,

Vskid3 was correct they were stock wheels from a 2010+ Prius. My old car was a 2002 Toyota Celica. The 16" stock alloys I removed were around 21 lbs, and the 15" prius wheels were around 14 lbs. The tires were lighter too, I don't remember the specifics on those. That wheel and tire combo is still going strong on my brother in law's car, as I swapped on some other less valuable wheels and tires prior to selling.

Thanks, aardvarcus.

Hmm. It is damn frustrating to try to get wheel weights on just about anything, let alone accurate weights. I was trying to find weight info on the Prius wheels, b/c of your suggestion, and the best I can find is posts from Joe-Schmoe on different forums. I wish the mfg's would release official #s on this. So, the info I could find on my steelies, a Corolla steelie, and '05 and '10 Prius alloys, this is what I could find...

2007 Toyota Matrix steel wheels
--------------------
16x6.5": 5x100, 40mm offset
9.1kg (20 lbs)
--------------------
Weight from a post on matrixowners.com but the site is down right now. (Will try to add this later in an edit)
Other info: Toyota Matrix 2007 - Wheel & Tire Sizes, PCD, Offset and Rims specs - Wheel-Size.com

2007 Toyota Corolla S/LE steel wheels
--------------------
15x6": 5x100, 45mm offset
7.3-7.7 kg? (16-17 lbs?)
--------------------
Weight eyeballed from rather questionable sources online.
Other info: Toyota Corolla 2007 - Wheel & Tire Sizes, PCD, Offset and Rims specs - Wheel-Size.com

2005 Prius OEM alloy wheels
--------------------
15x6J: 5x100, 45mm offset
6.45kg (14.2 lbs)

Sample pic: http://static.cargurus.com/images/si...873362058.jpeg
--------------------
Weight from: OEM wheel weight - GreenHybrid - Hybrid Cars
Other from: Toyota Prius 2005 - Wheel & Tire Sizes, PCD, Offset and Rims specs - Wheel-Size.com

2010 Prius OEM alloy wheel
--------------------
15X6J: 5X100mm PCD, 45mm offset
7.4kg (16.3 lbs)

17X7J: 5X100mm PCD, 50mm offset
11.0kg (24.3 lbs)

Sample pic: http://images.newcars.com/images/car...-Side-View.png

--------------------
From: https://priuschat.com/threads/wheel-weight.64309/

oil pan 4 · 10-06-2016, 08:48 PM

Quote:

Originally Posted by MPGee

I assume you're asking me? I'm not trying to go taller (as in larger overall wheel+tire diameter), because I'd like my speedo & odo to remain accurate... Otherwise, how am I gonna know if I've actually improved my fuel economy?

Figure out what the difference between the new tires and old are and add that to the miles per tank.
I have found that most speedometers read high anyways.
Putting on bigger tires makes it read closer to reality.

HydroJim · 10-07-2016, 08:54 AM

A lot of this depends on your driving. If you mainly do highway, focus on Aero and tire height. If you do a lot of in town driving, focus on reducing weight.

If you can do both at the same time, go for it.

Do make sure that 15" wheels will fit around your brakes. The corolla and matrix share a lot, so they'll probably fit. But just make sure first. I'd personally save my money and just go for taller LRR tires with the same tread width.

MPGee · 10-07-2016, 11:49 AM

Quote:

Originally Posted by HydroJim

A lot of this depends on your driving. If you mainly do highway, focus on Aero and tire height. If you do a lot of in town driving, focus on reducing weight.

If you can do both at the same time, go for it.

Do make sure that 15" wheels will fit around your brakes. The corolla and matrix share a lot, so they'll probably fit. But just make sure first. I'd personally save my money and just go for taller LRR tires with the same tread width.

I do a fair amount of both hwy and city. The 15 inchers will fit, no problem, it seems. I took a peek under my car, and there's a lot of gap between the drums/rotors and the wheel.

It's looking like I'm going to go w/ my original plan. I found some 15" Corolla factory steel wheels WITH tires with decent tread on them, for a decent price. Only thing is that it's got 195/60R15 instead of the 195/65R15 that I want.

I'll probably just run them for a while to extract my $ worth, then change them out for the right size.

I believe the change from 16" to 15" factory steels will net me 3-4 lbs weight savings per wheel, and 10mm in tire width. I'm hoping this'll show up in fuel economy #s.

The local pick-a-part yard wants $49/ea for 16" aluminum, and $43 for 16" steel, and 15" aluminum for $44, 15" steel for $39.

With whatever I end up getting, I'll be sure to weigh & A-B test them.

Sidenote: When I originally purchased my car, I was test driving the '07 Corolla vs the '07 Matrix. I noticed how much smoother the ride was in the Corolla. It occurred to me the other day that perhaps part of the reason the ride was much smoother in the Corolla was that it was equipped with 15" wheels vs 16"? (15" is standard on the Corolla, vs 16" on the Matrix). Hmmm.