Will new rims lower my MPG?

Hey.... I got a 2002 Civic LX 5sp with stock 14" steel wheels and
hubcaps. Right now I do a lot of commuting and get about 39 to 42 miles per
gallon. However don't like the looks of the cheap looking hubcaps on my
Civic and was thinking of going to the nicer looking 15" or 16" Honda wheels
or nice after market wheels.

But, I really don't want to lose my good gas mileage that I'm getting
with my Civic.

I did some checking and my stock steel wheels, plus tires and hubcap
weight around 31 pounds. going to a new larger wheel and tire will add
around 10 to 15 pounds per wheel and tire.
I do a lot of atv riding and no first hand at the power you will lose
by getting a heavier bigger wheel and tire, so was wondering about the mpg
that all Honda owners here have experienced when they install new sets of
rims. Thanks for any advice, Rob.

 

Find lighter rims. 1 lb rotating weight = 4 lbs static weight wrt
acceleration, braking, etc. Narrow rims will get better mpg than fat rims,
but probably result in poorer handling.

 

you may never again know what your mileage is since the larger wheels
will cause your speedometer and odometer to read low.

 

Whoever installs the new wheels should be able to find a tire rim
combination that has the same outside diameter as the original.

I question whether alloy rims would be mnoticeably heavier than the
original steel rims.



Elliot Richmond
Freelance Science Writer and Editor

 

You have already received some good advice; The following may help you with
your decision. Gear ratio's (tire and wheel size) directly effect your
milage and acceleration. I personally try to keep the same overall gear
ratio that the manufacture designed the car with. It's usually the best
combination of milage and performance. Go to www.miata.net/garage click
on wheels and tires, click on tire size calculator on right. Good Luck

 

I would find some good used Honda OE aluminum wheels from higher trim
versions of the Civic. If you go up to 15" rims you will need to use
lower aspect ratio tires in order to keep your speedometer reasonably
accurate.

Reasonable sized aluminum rims of quality manufacture should weight less
than steel rims, so something seems odd about your situation.

John

 

Where did you get those figures?

As all have said, the idea behind aluminum/alloy wheels is to weigh
*less*, I think you might check again, go to some reasonable nearby
dealer and weigh the stuff yourself if you have to!

Larger wheels suggest lower-aspect tires, which will weigh less. For
a given size, more wheel and less tire might weigh a bit more for
decorative wheels, if you're really that serious, I'm sure you can
find some wheels lighter than others.

Bottom line is it's unlikely to matter beyond cosmetics.

J.

 

Is it not possible to recalibrate Honda speedos for non-standard tire sizes?

 

I went to Tire Rack and for example took the 15" Borbet rims(several
choices) at 18.5 pounds then picked there recommended size tire 195/60/R15"
tires in lets say in a BridgeStone Potenza (Because I have a brother that
works for BridgeStone and can get a very big discount) at around 21 to 22
pounds which comes to around 40 plus pounds.

 

Thanks...that's a good calculator.

 

Sounds ballpark right.

And your current steel wheels and tires you weighed directly, I
presume?

Are the current tires 6.5/195 width? All I can think of, though it
shouldn't mean more than a pound or two.

Let's see ... ASA AR-1 15x6.5" "lightweight" at 15.9 pounds, Michellin
MXV4 at 195/60/R15 are 21 pounds. Hmm, BBS RG-F 15x7 are 10.2 pounds
for only $340! Others at 13 to 14 pounds around $120. SS-R
competition at 9.3, $289. Borbets seem some of the heavier rims.

FWIW

J.

 

Anything that makes the car heavier will reduce fuel economy. 40-60
pounds extra probably won't make a significant difference though. Cars
are a lot heavier than ATVs to begin with, so the PERCENTAGE weight gain
will be a lot less. Cars also have a lot more power, so the effect of
the added weight won't be as noticeable.

You might want to look for lighter rims, if you're that concerned about
it. Also, try to get a lower-profile tire that will give the same
overall outside circumference, or expect your speedometer and odometer
to read wrong (smaller circumference will make the speedo read higher
and the odo tick over faster). Any decent tire shop should be able to
match up the new tires properly.

Remember too that wider tires will increase your rolling resistance and
that will negatively affect fuel economy, though it will improve handling.

 

I found the weight of my stock 02 civic 14" wheels by weighing myself then
removing the steel wheel and hubcap and holding both standing on the scale.
It was a very good new scale so am pretty sure of the results and did it
three times to be sure of the weight. I was very surprised at how light the
set up was myself. I thing this is one of Hondas Civci's secrets for there
good gas mileage.

 

My stock tires are 185/70/ 14" on my 02 Civc.

 

The BBS RG-F are 10.2 pounds but that's $340 per wheel, don't have that kind
money for a whole set. True some wheels weigh less than Borbets but if you
look at the whole lot of wheels that fit the Civic the Borbets are on the
lighter side plus there prices are some of the best for a high quality
German made rim. But it's going to be tough to match my stock Civic hubcap
set up for weight. Later, thanks for the looking.

 

I have to say I had potenzas (RE92's) on my 01 maxima, and man they were
Horrable!, they wore out in about 23,000 miles, were really bad in the snow,
and less than average in the rain. only thing they had going were they were
pretty decent on dry pavement. but for teh price they ask, and for how long
they lasted, I'd NEVER get them or recommend them again. (now your discount
might change that for you) but personally, when I replaced them with
Yokohama Avid V4's it was MUCH better all around (rain, dry and snow) and
more than half the price than the bridgestones.

 

Increasing weight on wheels have a higher effect on increasing weight
than, say, inside the car. The wheels and suspension pieces are
unsprung weight. This is much more significant than sprung weight.
Consider this: Wear a backpack with 20 pounds in it and run. You
won't feel a big difference. But if you put 10-pound weights on each
foot and ran, you will be much slower.

In addition to reducing gas mileage, it makes the handling worse
(other than the added mechanical grip with wider tires), makes the
ride harsher, increases braking distance, and slows down acceleration.

Lighter or equivalent wheels are indeed possible even though the rim
size increases...if you're budget allows it. Keep in mind some tires
are heavier than others too. That weight is actually more critical
than the wheel weight.

 

Another secret for their good gas mileage is their tall gear ratio.
My's sister Civic EX, which has a 5-spd manual, was the only I car I
drove that lost speed while going up one of the steep hills in my
city. When I floored the gas pedal, it still lost speed. A down
shift was necessary.

I'm not knocking the car. I'm just augmenting upon your comment on
how they achieve their good gas mileage.