Fuel Economy Tip - Don’t Get “Sweet” Rims
May 23rd, 2006 | by Brian Carr |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.
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.
25 Responses to “Fuel Economy Tip - Don’t Get “Sweet” Rims”
By Anonymous on May 23, 2006 | Reply
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.
By penty on May 23, 2006 | Reply
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.
By geeknip on May 24, 2006 | Reply
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.
By Brian Carr on May 24, 2006 | Reply
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.
By KeplerNiko on Jun 13, 2006 | Reply
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.
By Anonymous on Jun 14, 2006 | Reply
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.
By Lucas on Jun 14, 2006 | Reply
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.
By Alex on Jun 14, 2006 | Reply
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).
By Anonymous on Jun 14, 2006 | Reply
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..
By Brian Carr on Jun 14, 2006 | Reply
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.
By Anonymous on Jun 14, 2006 | Reply
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.
By Ace on Jun 14, 2006 | Reply
The first comment left is absolutely correct. HOWEVER — I think the point being made was to not buy the “bling bling” rims that probably weigh 40-50 pounds a piece and are obviously too big for the car. You know, the guys that put 20″ rims on a Dodge Neon with tires so wide they stick out 2″ from the car.
I took the lighter rims route on my car. I dropped 14 pounds per wheel while maintaining the stock tire width and height. It made a difference of 2mpg, which in my 25k+ miles per year case is a pretty big savings over the course of a year.
By penty on Jun 19, 2006 | Reply
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.
By Anonymous on Jul 31, 2006 | Reply
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.
~
By Anonymous 2 on Jan 5, 2007 | Reply
Wow I have really got a good kick out of this artical.
There are more than a few factors at play; first of all if you have more contact with the road you are going to have more resistance regardless of how you try to justify it, however I highly doubt it will affect your economy drastically because by using a wider tire you are also displacing the weight of the vehical over more area which means your contact with the road has less weight per square inch on it (thus slightly less ristance; same reason why people put weight in the back of trucks when it snows). Secondly, your vehical (this is espeically true with newer vehicals which have numerous sensors that will adjust your fuel delivery based) is designed for an optimum diameter which you should try to maintain by using lower profile tires on larger diameter rims. Just ask anybody who has huge oversized tires on thier 4×4 (and has not adjusted axel or gear ratios) what they get for gas miliage. Finally weight is a MAJOR factor, once a wheel is spinning at a consistant ratio it does not require a lot of energy to continue spinning (yes this would be because the inertia of the wheel is present). However both starting and stopping a heavier wheel requires more energy.. go ahead and strap on a bunch of lead weights to your bicyle wheel and then try to climb a hill.
I guess the final point I wanted to make was that you can achive much better gas milage by using a lighter & slightly larger rim (less tire weight for low profile tires), but another thing to consider is that by increasing your contact size with the road is going to give you a safety advantage as well by decreasing your stopping distance and giving you better all around handeling.
Hopefully this puts an end to this artical… unless I have make a spelling “misteak” somewhere that enevatibly some jackass will use to discredit me
Drive safe folks,
By no one on May 2, 2007 | Reply
id like to start off by saying bigger rims as in diameter actually in crease ur over all gas mileage on the highway but it does reduce ur gas mileage in the city. so sorry u only have half the storry right and if u drive on the highway more often than in the city the investment of bigger sweeter looking rims could actually pay off.
By stevo on May 22, 2007 | Reply
Hey,
I just stumbled onto this blog….wow…1st of all anon 2 you wrote, “I love this artical”??..huh….yo how bout an english class…its article which is what you should learn to spell if you want to blog for the public to see and read. Anyways as far as the POS issue….your best bet is to just drive a POS or those 20’s or 18’s or whatever you flossin’….those gonna get ripped off in da hood…come out car be on jacks n stuff…know what I’m sayin cuz?
By Anonymous on May 29, 2007 | Reply
Stevo you are so ignorant, you should read the whole article because he said, “unless I have make a spelling “misteak” somewhere that enevatibly some jackass will use to discredit me.”
By BEATRICE on Jun 22, 2007 | Reply
SIMPLE. YOU WANT A BETTER LOOK FOR YOUR CAR AND BETTER HANDLING? GET HIGH PERFORMANCE WHEELS OR RACE WHEELS OR WHATEVER YOU WANT TO CALL IT. THEY ARE DESIGNED TO BE LIGHT AND TO LAST AND NOT CRACK. THEY MIGHT BE A LITTLE MORE BUT REMEMBER YOU GET WHAT YOU PAY FOR. PERFORMANCE WHEELS ARE LIGHT. IF YOU ARE CONCERNED ABOUT GAS MILEAGE DONT GET ANYTHING HEAVY OR ANYTHING LIKE THOSE SPINNER THINGS.
By JIM on Jun 27, 2007 | Reply
A few people actually have it right, light wheels create less rolling inertia than heavy wheels so you will get better gas mileage. So if you replace your stock 16 in steel rims with 20 inch aluminum rims generally you will get better gas mileage. If you replace your 16 inch steel rims with 20inch steel rims you will get worse gas mileage. A wheel is like a donugut, most of the wight is far from the center of the wheel. If the wheel weighs 20 lbs and you move that weight 4 inches further from the center of the wheel it will take more energy to move it and you will get worse gas mileage. On the other had when you replace that 16 inch steel with a lighter 20″ aluminum, generally you will get better gas mileage because even though most of the wheels weight is farthur from the axle, you are moving less weight and the tire has a lower moment of inertia. You would get the best gas milage by replacing your 16in steel rims with 16 inch aluminum rims.
The posters who talk about larger diameter wheels increasing the size of how far you travel on one rotation are a little off. When you increase rim size you decrease the rubber ‘thickness’ so the overall diameter of the rim and tire is about the same whether you have 16 inch rims or 20 inch rims.
Personally I added 20in aluminum rims to my Tahoe because I liked the looks. Three weeks latter I took them back because since I had to have lower profile tires to keep the overall diameter the same, the ride sucked. There wasn’t enough tire to soak up the roughness of the road and the Tahoe’s springs and suspension weren’t designed for it. Performance (handling) was better with a lower profile, wider tire. But, ride quality suffered. I have a SAAB that I added lighter weight bigger aluminum wheel and I ended up with better handling and better milage since the SAAB’s suspention could handle the rougher ride.
By Chris on Oct 15, 2007 | Reply
Pathetic. Whatever the argument, the insults just reek of “Im better than you”. People who drive a 70k+ car can get spinny rims..they are showing off and thats ok. People who drive a 88 honds civic and put spinny rims on it are the ones that kill those of us who care about our lives. They need to have thier car taken off of them and deported back to mexico, the ghetto, or wherever they are from because it certainly isnt anywhere where education is prevelant.
By Anonymous 24 on Sep 28, 2008 | Reply
Well thanks guys for the advice even if you still argue ,i just have a simple question atm i am using a hyundai accent 2004 with dohc engine 1.6 it have 14 inch wheel 185\60 i was just wondering can i change it into 15inch 195\55
i dont think its sport car but am just looking for more stablity & handling & same fuel consuption without affecting the adometter or the suspention
because when i added a 16 inch wheel 205\45 the car wasnt stable even the steering wheel was shaking so bad
By hubzap on Oct 13, 2008 | Reply
Anon 24, the right size you should “Plus size” to is 195/50 R15, if the original size is 185/60 R14. Check a site like TireRack.com, they explain how to adjust tire size when upgrading wheel size so the new wheel/tire combo fit without throwing off your speedometer readings.
On the whole weight issue, you just can’t take it to an extreme:
16 inch steel wheel weighs more than a 16 inch forged alloy wheel.
16 inch steel wheel weighs the same or LESS than a chrome-plated wheel, b/c the plating makes an alloy wheel heavier.
16 in steel wheel weighs LESS than a 22″ chromed-out spinning set of Dubs, b/c of the aforementioned chrome, plus the additional spinning hardware.
Even in light alloy wheels, if you go to an extremely large size, you’re dramatically increasing the weight of the wheel, which cancels out the weight benefits. Again, check out tirerack.com or discounttire.com and look at the weights of wheels rise by about 2-4 lbs. PER SIZE.
Now for the TIRES: usually when you get big rims they’re accompanied by high-performance tires that are biased towards tons of grip, not low rolling resistance…aka lower MPG.
The trick is to buy a lightweight alloy wheel, match it with a low-rolling-resistance tire and if you’re going to get a larger wheel, go up no more than 2-3 sizes (ride comfort will get shot beyond that anyway).
If you look at Honda, up until recently their high-performance versions of cars did not have big wheels…even their high-end NSX sports car had 17s (and I believe 18s in their last 2 model years), b/c you reach a point where big wheels become a heavy burden & increase unsprung weight (look it up), no matter of what alloy it’s made out of.
I’m not a follower of Newton or Galileo or Socrates or Einstein or whomever; I’ve just had the experience of putting heavy chrome wheels on my own car as well as others back in my heyday. The big wheels increased grip tremendously, at the expense of steering feel (much more numb) and MPG.
Now that I’m older (and hopefully a bit wiser), I only upgrade 1 or 2 sizes up, and look for the lightest decent-looking wheel possible (not flashy!) and match it to an all-season low-roll resistance tire.
By Anonymous on Nov 14, 2008 | Reply
Ligher tires are eaiser to accelerate thus good for driving with frequent stops and speeds changes.
Heavier tires are easier to maintain at a constant speed. Thus good for highway milage, or for driving that doesn’t stop or change speeds often.
RMP at 1,000 takes more gas than RMP at 10,000
To a practial point, the less contact area the more efficient.
Forget Newton or Gali the ideas you all are thowing around are way beyond basic physics. Various cars will have a nonlinear reaction to changes in their drivetrain.
By Daniel Johnson on Dec 2, 2008 | Reply
Don’t know if this has been mentioned, but your car will get the best mpg when the motor is running at the peak of it’s torque output. For my car that is right around 3000 rpm. This is not to say, that 5th gear at 1000 rpm is better than 3rd gear at 3000, but that once you pass your peak torque in any given gear your mileage will start to drop.
Circumference plays a part in the mileage factor, but is often offset in that it pushes the weight that needs to be spun further from the axle, so usually you don’t see a gain or loss from that.
The best is to have a light wheel that has as much weight as it can towards the center. The closer the weight is to the axle, the easier it will spin.