weight of wheels/tires

TheStepChild · #1 07-29-2012, 08:50 PM

When shopping for aftermarket wheels is it as simple as choosing the lightest weight wheel?

F8L · #2 07-29-2012, 10:57 PM

No.

Wheel weight is important but so is offset and aerodynamics. If you change the offset from stock by decreasing offset such that the wheel sticks out into the airstream then you could lose mpg. Wheel upsizing can also reduce mpg quite drastically despite keeping wheel weight the same. In the Prius world, upsizing from a 15" to 17" wheel (maintaining OE rolling diameter) can drop your mpg by as little as 3mpg to as much as 8mpg depending on driving style.

Tires are much more complex and weight doesn't tell the whole story. You're best bet is to stick with a low rolling resistance tire that has been tested against other LRR tires so you can see how they rank. Not all LRR tires are created equal so one tire may provide much better fuel efficiency than another. Some of the best: Energy Saver A/S, Ecopia EP100 amd EP422, Assurance Fuel Max, dB Super E-Spec, Nokian enTYRE, Primacy MXM4, etc..

TheStepChild · #3 07-30-2012, 05:35 AM

thanks!

I'll have to check off set. My first choice (based mainly on weight) might be bad aerodynamicly. Back to the shopping.

Not planning on upsizing any. I want to stick with stock size tires.

PaleMelanesian · #4 07-30-2012, 09:47 AM

Remember that you can change the aerodynamics after the fact. You'll have to be more creative with alloys vs steel and hubcaps, but there are ways. I'm sure you are more than capable of doing so.

TheStepChild · #5 07-30-2012, 11:13 AM

My 'plan' is to run the stock oe tires & wheels until winter. Put winter tires on the stock steel wheels. Then Have a better tire wheel combo lined up for spring.

CPLTECH · #6 07-30-2012, 07:26 PM

When it comes to good mileage, sometimes the mfg did their homework matching tire size to the optimal cam for the motor and weight of vehicle. A friend had a 5.0L, 5sp MT, dual exhaust, 1985 Mustang and was able to get 28MPG on trips. Amazing, all that power and good mileage, too. Seems Ford had engineered everything just so on that model. At the time I drove a stripped down 78 Chevy 3/4T work van, 5.7L, 3sp MT and no mater what I did, got 15MPG. Then decided to put some tall tires on it to change gear ratio and got 18 on a trip. So gearing was the culprit for the type of driving I did most. Then put in a slightly wild cam and was then blessed with 14 MPG.

As an experiment, I figure you could try a set of tires just one size taller (not wider) to see what happens. (Yes, it will lengthen your braking distance) That may help someone who does a lot of highway driving, whereas a size shorter tire may be more advantageous for the city driver. Of course, any changes will change speed, odom, MPG calculations. Wonder if a 6sp MT would give you the best of both worlds as you closely watch the ScanGauge???

F8L · #7 07-31-2012, 09:48 AM

What size tire are you looking at? I can check my resources and see which one would likely offer the best mpg or have the lowest cost/mile to run.

TheStepChild · #8 07-31-2012, 11:25 AM

205/55/16

Looking at a set of Michelin x-ice xi2 for winter http://www.tirerack.com/tires/tires....odel=X-Ice+Xi2

Unless I can find something used locally. I found a set of Bridgestone Blissiaks on CL but the guy hasnt emailed back yet. Might make the purchase this month on a set for winter.

For next spring I'm looking at :
Michelin Defender http://www.tirerack.com/tires/tires....Model=Defender

or

Goodyear Assurance Fuel max http://www.tirerack.com/tires/tires....rance+Fuel+Max

PaleMelanesian · #9 07-31-2012, 12:04 PM

Nice. I'm a big fan of the Fuel Max, having them on the Odyssey. They don't come in 13's for my Civic, so I'm leaning toward Defenders for my next set there. Michelin rates them better than my current Destinys (now discontinued) on all counts except "comfort", but I can live with that in my econo/fun car.

phoebeisis · #10 07-31-2012, 01:54 PM

I actually "weigh things" used to fool with bicycles-and motorcycles and caught "weight weenie disease" still have it
The best way- if you don't have a balance scale at how- to weigh "big stuff"
is to go to one of those PO that have a scale in lobby-open Sat and Sun
Put cardboard-weigh it-on scale-put tire wheel on scale-

On 17" wheels-oem-for 2004 Nissan Titan
17"Steel stock wheels- 31lbs
17" factory option 17" aluminum alloy wheels- 25.5lbs
17" Centerline FORGED ALUMINUM ALLOY WHEELS- 20.25 LBS
They were all 7.5" wide I think-all took the same 245/75 17 wheel(think that was the size)

So forged aluminum alloy wheels can be a LOT lighter than factory cast aluminum alloy.
Now how much MPG difference will 5 lbs make- my guess is nothing you could actually measure with the methods we have- it will be better in city driving(assuming aero stuff is roughly equivalent)- but it sure won't be 1mpg better which I suspect it our resolution for fill-drive refill calculations
Charlie
PS I noticed my brother's Infinity I or G or something or other 5 passenger "sports car" 295 hp 6- has FORGED WHEELS FROM THE FACTORY. So maybe you can find cheap factory forged "take off" wheels?? Guys LOVE to pointlessly modify change perfectly good OEM stuff-so.... maybe Lexus makes a forged wheel that would fit a Prius or Scion or Corolla or Camry??-Same story Honda and Acura??
My Centerline wheels were on sale-$600-usually aftermarket forged wheels are $200 each last I looked