[Bush Pilot]

Has anyone thought of installing the lightest possible wheels onto their car to maximize gas mileage? Keep in mind that the wheels on our cars are a tradeoff between performance and gas mileage. I wonder what wheels and tires are available?

[Welcome to NBA Jam]

A 328i

[Ghazi369]

335i with good gas mileage? The only way I'd think that's achievable is driver mod . A good set of tires would probably help but that's assuming the current tires and rims you have aren't any good.

[e90yyc]

The concept of using lighter wheels to reduce unsprung weight and improve performance is commonplace, but I doubt many people are replacing their OE wheels with lightweight wheels just to improve fuel economy. The ROI just doesn't make sense.

As you probably know there has been considerable advancement in reducing rolling resistance of tires, thereby improving mileage, but I've always considered the worthiness of a tire based on its performance and not on how much it weighs. My guess is that any weight difference between modern tires of the same size and category would be immaterial, but maybe I'm wrong...

I'm not sure I understand your statement about having to trade off between performance and fuel economy. I'd say the wheels on our cars are more a balance of cost on one side with performance and fuel economy on the other.

[Bush Pilot]

I’m envisioning a skinny set of wheels and tires to replace the wide ones my 335i has. When I compare the weight of these massive wheels to the ones my E30 rode on the difference is large. And if I’m willing to give up performance to gain gas mileage, why not?

[tcphoto]

What do you currently have on the car, run flats or standard tires, expectations for mileage? Perhaps others will share their performance, I get 20 City/29 Hwy on Style 189’s and Michelin PS4S 235/40/18 and 265/35/18.

[Brian86]

Tire and wheel weight in and of themselves are almost entirely trivial to fuel economy.

When choosing a tire for gas mileage:

Non run-flats
Low rolling resistance tires.
Narrower tires
Over inflate the tires.

Note the latter three will all decrease the available traction.

Sticking a rock hard low rolling resistance tire, in a 205 width, and inflating it to 45psi might net you a 20%+ improvement. Of course it'll be like steering with a boat rudder and stopping distances will be frighteningly long compared to the right size in a regular touring tire.

[Serf27]

BMW style37 wheels are light weight.
A square set up of fronts on all 4 corners would do well.
Could run 225 up front and 245 in the rear with the 8” front wheels.

[hassmaschine]

let's say you spend $3000 on new wheels/tires (probably too cheap) - all to save 2% on gas. Unless you're driving a lot of miles (tens of thousands) it's never going to pay off.

[white46]

Originally Posted by hassmaschine

let's say you spend $3000 on new wheels/tires (probably too cheap) - all to save 2% on gas. Unless you're driving a lot of miles (tens of thousands) it's never going to pay off.

second this.
You'll never pay off the price of new wheels and tires by the gas you are saving if any.

[e90yyc]

This thread confuses me.

[Bush Pilot]

Firstly wheel weight (rolling mass) has a large effect on gas mileage. Look at the wheels on a Prius. Look at the push to make bicycle wheels as light as possible.

Those making the "will never pay off" argument are assuming that I'm going to out and buy brand new wheels. I don't plan to do that. I think the payoff is an interesting study but I don't know the results of the study until I know what the potential path forward is.

I'm simply searching for potential solutions to what I hope and believe gas prices are going to do which is rise.

[ctuna]

BMW's are not fuel efficient vehicles .
Also they require warm up and a straight flat road with
no traffic maximize there mpg's .
At least true for the e90's and earlier .
In town stop and go and short trips are the worst.

[hassmaschine]

gas prices aren't even close to what they were in 2008/2009. I don't get why people are complaining. even in WA, which is only rivaled by CA and Hawaii for high gas prices - I pay under $4 a gallon for premium? Or maybe the actual costs have finally reached the rest of the country..

anyway, I didn't say it wouldn't make any difference. Of course lighter wheels have benefits. But most people probably don't spend $3,000 a year in gas, much less enough for a 2% savings to make a meaningful difference to pay off. It would take me eons to make back even a couple hundred dollars in gas savings.

It's the same reason buying a brand new EV (or newer car in general) to save money on gas makes zero sense - even if I'm a big proponent and investor of EVs, I wouldn't buy one right now because I'd never be able to make up the $40,000 difference. I'd rather spend $3,000 a year in gas for the next 10 years and invest the up front $37,000 (or just not have a car payment to begin with).

The Prius also uses a rock-hard tire that as as little rolling resistance as possible. That is pretty much incompatible with the idea of a 335i - sure, you could do that too, but then why bother with a 335i?

Now, if you want to talk lighter wheels for their benefits in handling, acceleration and braking.... I'm game! Wheels on modern BMWs are ridiculously heavy. I'm pretty sure the 14" set I used to run on my E30 weighed close to 1 rear wheel/tire on my E90..

edit: funny, I pulled $3,000 out of my ass. Curious, I looked up what I spent on gas for 3 cars last year - with road trips and high WA fuel prices - and it was $2900.