'16 OEM wheel weights & options

Yesterday I had a chance to weigh a set of OEM '16 Prius 15" alloys (15x6.5 ET40) w/Bridgestone Ecopia 422's (195-65-15): ~38 lbs (w/out plastic hubcap)- which is exactly what my OEM Gen 3 Prius wheel/tire combo weighed .

(Side note: Even though the OEM '10-'15 Prius 15" wheels were said to weigh ~16.3lbs? In either case Gen 3 or Gen 4 the scales read ~38lbs for the tire/wheel combo. Tire Rack claims the Ecopia's weigh ~19lbs. Based on this, both 15" OEM's combos should have weighed ~35lbs... where is the extra 3lbs coming from?)

I'm curious to see how much Toyota's $899 10-spoke 15" alloys weigh... anybody have a set?

I'm looking to potentially reduce rotational mass without compromising the '16 Prius' excellent 0.24 Cd. As an important side, would prefer not to increase LRR with a poor tire choice. (From what I have read there is NO mpg benefit in going with 17" wheels & low profile tires)

I had a set of 11.9lbs Motegi Traklites 16x6.5 ET50 in my Gen 3 Prius. Unfortunately, with 205-55-16 Bridgestone EL-400 (note not a LRR tire), the wheel/tire combo weighed about the same as stock: ~38lbs. My Gen 3 suffered no ill effects from this wheel/tire combo; returning the exact same overall 49mpg I had experienced since day one.

Perhaps there are lighter LRR tires out there in 195-60-16. Michelin Energy Saver's are purported to weigh <18lbs in that size (if they can be found).

Thoughts?
Just trying to see what options we have to positively "eco-mod" the '16 Prius.

Thanks in advance.

Here are a couple of shots...

I plan to swap out the 205-55-16 Bridgestone EL400 with Michelin Energy Saver 195-60-16's. Will report on weight & FE impacts if any.

Side note: I am astonished that Toyota claims they achieved a laudable Cd of 0.24 with such large wheel gaps!




Some numbers:
baseline:
Prius 2 Eco, OEM 15" wheels & Bridgestone Ecopia 195-65-15 with wheel covers ~38lbs.
~54mpg

I finally found some Michelin Energy Savers in 195-60-16. Weight 17.6lbs each with reportedly similar if not lower RR than the stock Ecopias.

Motegi Traklite 16x6.5 et50 ~11.9lbs. Including TPMS, & forged aluminum 5mm wheel spacers (to more closely approximate stock wheel's et40), total wheel weight is expected to be ~30lbs.

-8lb reduction in rotating mass (~+20%) per corner with a slight 1% increase in wheel height... will report on how this +30lbs loss of rotating mass works out in the next few weeks.

I expect small (if any) FE gains, but with a welcome bump in acceleration & handling feel. All in the name of hypermiling.
Now, slow down & drive safe!

As expected I weighed the Motegi Traklite + Michelin Energy Savers prior to install & the total weight for each was a hair over 30lbs vs. stock ~38lbs.

Without the benefit of a calibrated accelerometer, I can say that by the "seat of the pants," the Gen 4 feels improved over stock. Acceleration, turn in, & cornering all feel crisper. This is not just a placebo effect...

But that should be expected after losing ~8lbs of rotating mass per corner, or ~32lbs total. Lost weight where it counts most.

Too early to tell on FE impact- if any. I suspect aerodynamic drag may be adversely affected- due to the increased effective et45 vs. oem et40 & the porosity of the Motegi's 5 spoke design vs. the near disc-like surface of the oem wheel covers.

Is it worth the expense to upgrade? Unless you are a driving enthusiast like me, I suspect the FE gains (if any) will never add up enough to recuperate the cost. But since I already had the Motegi's gathering dust in my garage, what the heck.

Will keep posting FE updates as I drive more miles.

Enjoy the drive!

 

After install update:
482.4 miles / 8.91 gallons = 54.14mpg

As suspected, absolutely no change in mileage after installing the 16x6.5 Motegi Traklites with Michelin Energy Saver 195-60-16. Recall that this aftermarket tire/wheel configuration is ~8lbs less rotating mass per corner, for a total ~32lbs less rotating mass.

Lost weight where it counts most- significantly lighter than the stock 15" tire/wheel - however at highway speeds the more porous 5-spoke Traklites are perhaps less aero than the disc-like oem plastic wheel covers.

I will have to do a mostly highway tank mileage test to see just how un-aero these wheels are.

Preliminary conclusion: unless you really, really value small improvements to handling (namely acceleration & braking), save your money & keep the stock wheels!

After four US iterations, the Toyota engineers have truly optimized this vehicle & there's not much mpg gains available for the aftermarket crowd. Well done, Toyota.

 

Good news:

No ill effects to mileage at highway speeds: last two tanks 54mpg & 62mpg with mostly highway driving. Overall fuel economy has shown a huge improvement due to warmer ambient temps.

It may help that I never corrected the wheel offset. OEM offset 40mm- these Motegi's are 50mm- therefore the wheels sit 10mm further inboard than stock. Not ideal- but didn't want to have to change the wheel lugs.

So the non-aero Motegi wheels appear to be well-shielded from the airflow at hwy speeds by the car's body panels- at the expense of a slightly narrower tire track front & rear.

54-62mpg is nothing to sneeze at- when you consider I have used no hypermiling tricks to achieve this.

Prius Two eco

 

DeadCannon
What is the weight of your 15" Prius factory 10-spoke wheels?
Thanks!

 

DeadCannon, my condolences on your loss.

My 16x6.5 Motegi Traklites with Michelin Energy Saver 195-60-16 reduced rotating mass to the tune of ~8lbs less per wheel(!) compared to Toyota's standard Prius OEM 15" wheel/tire combo w/wheel cover.

A significant ~32lbs reduction in rotating mass- but alas, apart from "handling feel," i.e.: acceleration & deceleration, I have experienced no visible impact to my personal FE.

Now that my Prius is broken in, I'll try to measure 0-60mph times, & 1/4 mile times/trap speeds to help quantify exactly how much losing ~32lbs of rotating mass might have improved acceleration vs. published stock times.
Here are the numbers to beat:
'16 Prius Two Eco: 9.4 sec, 17.2 sec @ 81mph source: Car & Driver
'16 Prius Four: 9.7 sec, 17.4 sec @ 77.6mph source: Motor Trend

Since my car is a Two Eco- I'll try to compare to Car & Driver's results.

My guesstimate is that the gains (if any) will hardly be worth the expense of buying $$$ aftermarket forged wheels.