Help with wheel choice

[Wmvdg123]

So I have a 2005 sienna and on the highway I get about 30 to 35 miles per gallon on the highway. I’ve changed oil to 0W-20 and this helped quite a bit. I’m wondering if changing from the stock 16 inch wheels (22 lbs) to either some lightweight, aftermarket wheels (16 lbs but not aerodynamic) or some steely’s (22 pbs) would improve my gas mileage. I have on Ecopia tires.

It would seem intuitive that lighter alloy wheels would get better mpg, but but I’ve seen a couple posts were people mentioned that the Steelers get better mileage than they got with alloy wheels ironically.

Thanks!!!
Wayne

[cRiPpLe_rOoStEr]

Most likely the alloy wheels which could be disfavorable to mileage have worse aerodynamics, yet as a rule of thumb an alloy wheel with a more similar design tends to be better mileage-wise.

[Blacktree]

Generally speaking, aero trumps weight, when it comes to mpg. I'm sure there are some extreme cases where this isn't true... but those are extremes. So for example, steel wheels with smooth wheel covers are going to get better mpg than lightweight alloys that aren't aerodynamic.

[Ecky]

Get some expensive lightweight alloys and zip tie coroplast rings to them. Best of both worlds.

For what it's worth, I've been keeping an eye on aftermarket 16" options myself. RPF1's come in around 13lbs and aren't all that expensive. Next step up is forged ($$$), where you're looking at TE37's (11.5lbs) or T66-F (10.5lbs).

[cRiPpLe_rOoStEr]

Originally Posted by Blacktree

Generally speaking, aero trumps weight, when it comes to mpg. I'm sure there are some extreme cases where this isn't true... but those are extremes. So for example, steel wheels with smooth wheel covers are going to get better mpg than lightweight alloys that aren't aerodynamic.

A few months ago, while taking the dog for a walk and stopping at a gas station to get a coffee, I had a talk with a lady who was considering to not keep the wheelcovers of her 3rd-gen Prius after having a flat tire changed. Ultimately she figured out it would be better to keep the wheelcovers for aerodynamics sake.

[Wmvdg123]

Thanks for the report, i think ill try the RPF1 with some coropladt. Thank you!!

[Nissandriver]

I prefer lighter wheels. The car handles better, is quieter, and rides smoother.

Many years ago, I went from steel wheels to alloy wheels on my 240SX. At the time I made a 50+ mile commute to work 5 days a week. My mileage remained the same even though the alloy wheels and tires weighed more than the steel wheels and tires. The alloys had 215/45/17 tires and the steel wheels had 195/60/15 tires. I expected the larger wheels and tires to reduce my mileage but I was pleasantly surprised that they didn´t.

The improvement in ride quality with a lighter wheel/tire might be much better than any difference in mileage.

[Nissandriver]

Originally Posted by Ecky

Get some expensive lightweight alloys and zip tie coroplast rings to them. Best of both worlds.

I need to try that on my Sentra. My wheels are light but I doubt their aerodynamics are very good. I don´t want to do anything to my car that can´t be easily returned to original so I´ve given up any idea on a boat tail, kammback, or wheel skirts but I think I can do a grill block, undertray and possibly a rear diffuser.

[aerohead]

It's really about 'polar moment of inertia' ( flywheel effect ).
If a 'heavier' wheel has its mass concentrated closer to its 'center', than a 'lighter' wheel, it could be dead-heat!
I think Stellantis is offering an $11,000 set of wheels for the Dodge Challenger SRT Demon 170, which are carbon-fiber 'rims', bonded to aluminum 'spokes', held on by titanium lug nuts. Extremely-low polar moment.
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These same wheels would gut your mpg on the highway though, as they'd have as high an aerodynamic 'windage'-'ventilation' drag as you'd likely find.
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Even if you did nothing but stop-and-go driving, and considering the overall mass of the Sienna, I don't know that a lighter wheel would even move the dial.
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On a hybrid, plug-in hybrid, and BEV they might even reduce efficiency, as regen could suffer from the reduced inertia/momentum.
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If we had Toyota's numerical modelling software we could resolve the issue virtually.

[cRiPpLe_rOoStEr]

Originally Posted by Nissandriver

The improvement in ride quality with a lighter wheel/tire might be much better than any difference in mileage.

Even more noticeable when it comes to a more spirited driving, which is inherently not so fuel-efficient at all...