Fuel Economy Tip - Don't Get "Sweet" Rims
Today's tip will help you save money on your gas bill and will keep you from spending hundreds or thousands of dollars on your car's wheels.
That being said, there is merit behind why you shouldn't put them on your car.
Your car will get better gas mileage the more "stock" it is, meaning it's the way the automotive engineers designed it. The more things you add to it, the worse fuel economy it's going to get.
Additionally, tricked out rims tend to need wider tires which, as you guessed it, reduces your gas mileage. The wider the tire, the more surface that makes contact with the road. That extra surface requires more energy to get up to and maintain speed, meaning more gas used.
Save your money and save your gas.
Admire other people's tricked out tires and rims, but don't put them on your vehicle.
First, I'd just like to explain that I do have a bias; I think spending money to put "fancy" rims and wide tires on your car is stupid and a waste of money. If you feel the need to waste that amount of money, go ahead and send me a check for $500.That being said, there is merit behind why you shouldn't put them on your car.
Your car will get better gas mileage the more "stock" it is, meaning it's the way the automotive engineers designed it. The more things you add to it, the worse fuel economy it's going to get.
Additionally, tricked out rims tend to need wider tires which, as you guessed it, reduces your gas mileage. The wider the tire, the more surface that makes contact with the road. That extra surface requires more energy to get up to and maintain speed, meaning more gas used.
Save your money and save your gas.
posted by Brian Carr at 8:16 PM
17 Comments:
A set of centerline forged aluminum rims at around 12-14lbs, will give better performance and fuel economy than any cheap OEM steel wheel or cast aluminium rim (25+ lbs).
Please educate yourself before spouting off your opinion.
Just because you enjoy driving a POS, doesnt mean other people shouldnt have fun tweaking - and improving their vehicles both cosmetically, and yes functionally.
hey anon,
You have to look at inertia as well as weight when looking at wheels.
Example, take 2 aluminum wheels one is solid and the other is a "ring". Roll them side by side down a slope.
The ring rolls slower because it has overall more momentum and therefore take MORE energy to spin.
Sure the pay off might still be thre or not. but it more complicated than you think.
It's just embarrassing for soe to say "Please educate yourself before spouting off your opinion." then to be uneducated themselves.
how do nice "rims" change a POS to a "not POS"?
Seems to me adding sweet rims to a POS simply make a POS with sweet rims.
Needless to say, I agree with the last two comments. I don't think that adding rims to my car will take it from being a crappy car to a great one. And, you can't help but point and laugh at the cars that are worth $500 but have $800 rims.
penty,
Haven't you heard of Galileo? Two objects of different mass will nevertheless fall at the same rate. It's *gravity* that's working on them. On the moon, a feather will fall no faster and no slower than any other object--one of the astronauts demonstrated this fact.
So, don't call others out who tell people to get educated, especially when you missed a basic lesson of seventh-grade physics. I don't know what your argument is trying to prove.
The original anonymous is right. Tons of carmakers put cheap steel wheels with plastic covers on their cars. Replacing those wheels with lighter aluminum rims WILL improve your gas mileage.
Lighter = less energy to get moving = less gas wasted. It's that simple.
KeplerNiko:
GALILEO?!
Wasn't it Newton with the gravity bit?
That's all besides the point, though, because penty's comment was regarding rolling them down a decline, not dropping them from the same height.
To be sure, gravity does apply, but just lightening the weight of a rotational mass isn't going to solve all of your problems.
NONE of you have even contemplated the effects of tire/wheel diameter.
The larger the diameter, the better the gas milage.
The reason: increasing the diameter increases the circumfence [ c=2*Pi*(d/2) ], which means that the car travels farther during one revolution of the wheel/tire. This results in the engine turning a lower RPM for a given speed and thus better fuel efficency.
PS Newton was gravity, or specifcally force=mass*accerlation. Galileo was a mathmetican that dabbled in lots, most famos for his telescopes and celestial observations.
keplerniko: look up moment of inertia. You need a basic rotational dynamics refresher.
lucas: lower engine RPM does not necessarily mean better fuel economy. Your engine will get its best economy at a particular speed, and it won't be at 1000 rpm. In my car, it's around 3000-3500 (at least on the highway, where it's easiest to make these measurements because I can keep the speed constant). Also: you only get the same acceleration for falling bodies because gravitational force is proportional to mass (according to Newton anyway). Again, in this case, you must consider moment of inertia as well as just mass, since it requires extra energy to get something rotating (in addition to translating).
haha morons, first of all, aftermarket wheels usualy are wider which does increase the contact patch with the road, however the tires that fit these aftermarket wheels are low profile and are usualy inflated to a higher pressure which equates to less deformation of the tire on the road surface which in turn decreases the amount of rolling resistance which in turn increases gas mileage, and to the moron who thinks his car gets the best mileage in the 3000 rpm range, try that in first gear, at cruising speeds in the highest gear, lower RPM is going to give you better mileage unless your engine has a seriously crazy ass backwards powerband, so larger diameter tires and wheels are going to give you slightly better mileage for that fact alone, it is true that some larger wheels and tires have a larger rotational mass than some stocks, but if you buy "lightweight" wheels that most of which are nearly half the weight of normal steel ones, youre going to save on rotational mass even though the diameter is a few inches larger. take it from someone who has driven many junkers with nice wheels :) i have a dodge spirit POS now and i averaged 24mpg highway on my stock wheels and tires, just recently ive purchased a set of 16 inch lightweight rims and new tires, i havnt officialy recorded the mileage but a difference is obvious even wihtout the numbers, i'd guess its somewhere around 28 now. so everyone stop arguing, quit throwing around theories that have nothing to do with the physics of ..er...wheels..
Looks like this tip has been debunked.
Maybe I'll have to retract my statement and post a tip that you SHOULD get lighter rims. Just don't get those freaking spinning rims that make you look like a donkey.
Ok, setting some things straight:
Your car has a best fuel efficiency ratio at a certain moment in the powerband. Unless you have a sportscar, it's most probably somewhere in the 2000-5000 RPM range. Of course, it's not all over the powerband. My car (A 2.0L, 115bhp engine) has it's peak efficiency at 2500 RPM. Some cars (especially cars with less power), might have the peak efficiency at 4500 or somewhere around. This number is selected by the engineers when designing the car.
Of course, going at your peak efficiency in RPM in 1st is less efficient than going at peak power (about 1-15% of the RPM range below the redline) in 5th. Trying to compare these two conditions is stupid.
Second, increasing wheel diameter usually won't give you better or worse mileage, since the total output of energy is the same. What it will do is change the speeds at which you'll have the most efficiency. If your top efficiency is at, say, 60mph in 4th, then increasing your wheel diameter might change that number to 70mph. If you usually drive at 70, then yes, it will have better efficiency at the expense of worse efficiency when you're not driving at that speed.
Finally, bigger wheels require more energy to turn. Inertia (which is the resistance of the wheels to roll) is the mass times the square of the distance between the mass and the axis. So, if you reduce the weight in half, but increase the radius to twice the size, you'll have twice as much inertia in the wheels.
Oh, and Galileo has nothing to do with this discussion. The only moment where Galileo's gravity principle is when you're going up or down cliffs, where you have to add or substract the energy used to raise or lower the car's altitude to the energy consumed. Still, 40lb in a 3000lb car is completely negligible.
Basic mechanics, folks. Basic mechanics.
I was all set to "corrent" KeplerNiko but some already did.
"Gravity" and "moment of inertia" are 2 differnet things.
Your good eveidce that a little bit of knowledge is a dangerous thing.
How about just stop driving? Or selling whatever it is that you're driving that gets less than 30 mpg? Or taking public transportation? Or riding a bike?
Cars are not as necessary as many people think they are. They are mostly a luxury.
Sure, getting extravagant rims on a low-quality car is silly. However, to a certain extent, so is relying on your automobile so much! If you want to bling up your ride but don't want to pay any more in gas prices, don't drive the thing one day a week.
~
Hey, one of the anons up there has the same car as me! 2.0L 115bhp, I'm guessing a VW Golf? I've HEAVILY modified my car for optimal gas miliage. One thing I did was get lighter larger diameter wheels because I drive on the Beltway a LOT. They match my car and make it look better (I got a great deal on the wheels).
Anyway, I'm easily getting 33-40mpg depending on how impatiently I drive and one of the BIGGEST changes I've noticed so far was when I switched to lighter wheels. Also my turning radious and handling has also increased which makes me feel safer.
This is a terribly one sided post and it should be noted that not all wheels are "Bling" and some can be quite taseful.
I agree with you, that's why I later amended the post (did it in another article) and stated that some rims will actually HELP you save gas milage - so long as they were roughly the same size and made of a lighter material.
buy a motorcycle....solve this problem all together...
pwned
Yeah, for now I guess we (people reading this article and commenting) have solved the problem of what type of wheels are better for your car.
But in all honesty, the bigger issue is the future of automobiles... and it's probably not hydrogen.
At this point in the post, the (usually) 13-year old poster would go off on some technology some guy on eBay was trying to sell him that would help him make a car run on water.
But no, I'm not 13. I imagine that, if we make it that far in the future without blowing ourselves up, the future holds electric cars. As we increase battery life, battery capacity, and reduce the danger of carrying these batteries in our cars, electric cars will be the better alternative. This will go hand in hand with a move to "better" energy sources for energy plants, such as huge wind farms, wind kites (http://www.popsci.com/popsci/energy/062f2ec75919b010vgnvcm1000004eecbccdrcrd.html), and other such low-impact sources of power.
But that's just me.
Post a Comment
<< Home