will 16" Wheel & Tire affect MPG?

gearhead

Veteran Member
Joined
Jan 17, 2001
Location
Weirton, WV (close to Pittsburgh)
TDI
2001 Golf
How much will MPG suffer with a 16" Alloy rim (21 lbs.) and 225/50/16 tire over the stock steel, 198/65/15 combo?

What has been your experience? Any recomendations?

Thanks, Gearhead
 

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
Joined
May 1, 1999
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Canada
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TDI
Several MPG, by my experience.

The factors that affect fuel economy are tire selection, as well as thread width, tire height and combined wheel/tire weight compared to stock.

Two tires, despite even identical size, one an "eco" tire like Michelin Pilot Energy or Continental Eco-Contact compared to a max-performance tire will have a fuel economy difference of several percent. Rolling resistance is the reason, but this is a function primarily of the tire's compound formulation.

Wider tires increase the frontal area, thus aerodynamics are hurt. And contrary to popular thinking, wider tires do NOT necessarily contribute to a greater contact patch or better handling.

Wider and taller tire/wheel combinations have higher polar moment of inertia, and effectively makes the gearing taller (not always a beneficial side-effect). They have higher rolling resistance, and are quite often heavier (even compared to factory steel wheels).

The point is that these have implications on fuel economy (rolling resistance, increased drag), performance (greater inertia and rolling resistance) and handling (unsprung weight). The question is, what are you willing to compromise, and how much?

My personal scenario: A few weeks ago, I replaced the stock steel 6x14 wheels wearing 195/60-14 Badyear Eagle GAs on my Passat for 7x17 aluminum wheels, which at ~20lbs each are considered decently light in the 17" class. With new 215/40-17 tires mounted, I noticed they were immediately HEAVIER than the stock wheels they replaced. The new combo is about 14mm taller (a little more the 1/2") no big deal... actually corrects for conservative speedometer.

I'm sad, though not overly surprised, that my mileage has dropped from mid-to-high-40s MPG to the low-to-mid-40s.

[ September 04, 2001: Message edited by: tdimeister ]
 
M

mickey

Guest
A more precise match would be 205/55 16. That's what the New Beetle uses. The tires should be cheaper, too.

You'll give up a couple of MPGs because the tires are wider (aerodynamics) and have a larger contact patch (rolling resistance.)

"Worth it"? As a New Beetle driver, I'd say YES! The difference in tire prices will be pretty scary, though. Make sure you fully understand what you're getting yourself into.

-mickey
 

Wolfsburg Man

Veteran Member
Joined
Feb 9, 2001
Location
Denver, CO, USA
TDI
Jetta TDI GLS, 2000, Black
I have 16" TSW VX1 Alloy Wheels and it hasn't caused any loss of fuel economy on my 2000 TDI. If anything I would have purchased 17" wheels.
 

2GreenTdi's

Veteran Member
Joined
May 28, 2001
Location
Sootland
IMO Just going with the shorter sidewall firms up cornering enough. The need for 17" only comes into play when your autoXing. Then if you go to heavy they hinder you. Mickey, gave the ideal set up. I tried several including the 17"s and I found for day to day and the occasional romp, that's the set-up. 205/55/15 or 16" depends on how much mpg your willing to give up.
 

BRBarian

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Joined
Nov 11, 2000
Location
Chevy Chase, MD, USA
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Five Golf TDIs!
Have you considered a lighweight 15" alloy wheel? Thaks what I'd recommend.

It's a simple trade-off...

15" wheels give you better mileage, better accleeration, and shorter stopping distances (sometimes important).

17" wheels give you better cornering (and better looks according to some), but everything else suffers.

A 16" wheel is a reasonable compromise...

and 18" or 19" wheel just makes you look stupid (IMHO).
 

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
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Good points all. I want to add that I initially was planning on getting 16 inch wheels on 205/50 tires (more than 3/4" taller than my stock 195/60-14s), paying careful attention to choose a lightweight wheel. At first I was apprehensive about installing 17 inchers in light of the fact that some of the roads in my area must be among the worst in the country. I am pleasantly surprised to report that the ride quality hasn't detertiorated to the point of being unacceptable. In fact, in most road conditions, I can hardly tell a difference to my 60 aspect ratio Badyears inflated to 40 PSI (I run 35 PSI all around in my 17s now)

In hindsight, the prudent and smart side of me would have gotten the 16", but I succumbed to vanity
because the wheels I got are only available in 17" diameter or bigger.
 

jayb79

Top Post Dawg
Joined
May 20, 2000
Location
Exeter,NH
If the outside diameter of the tire stays the same a wider patch of rubber on the ground will cost you fuel economy. I went from 205/55-16s to 195/65-15s(basicly the same dia.) and got about 1-2 mpg increase.

A taller tire will reduce you final gear ratio. This will make for slower starts but more MPG's on the highway.
 

Birdman

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Joined
Apr 7, 1999
Location
Near Hagerstown MD.
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Jetta 2001 Died by Truck one snowy day. Jetta 2003
I loose 2 mpg going to 205s/16 in the summer. TDI Believer said his lose was 4 mpg on the 225s/16
 

Tinker

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Aug 21, 2000
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No fixed address (New England)
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Jetta, 1997, White
In my experience you lose MPGs as you go wider, size of the rim itself does not play that much of a factor in MPG. When you get larger rims you decrease ride comfort, increase looks (to some
), and increase the chance of bending a rim. I went from 195-65-14 to 205-55-15 and lost 2 MPG, but it was worth it, the steel 14s suck.
 

mik_ok

Member
Joined
Apr 24, 2001
Location
Scotland UK
A 225/50/16 has an almost identical radius to your original 195/65/15....rolling circumferance of tyre/wheel combo drops from 199.2cm to 198.3cm.....which reduces your gearing by only 0.5%. (If your speedometer is perfectly calibrated for 70mph on your standard setup, you'll actually be doing only 69.7mph on your proposed setup). In other words you won't notice!

Bear in mind that your gearing alters by almost 2% throughout the life of a tyre anway (assuming it starts with 8mm tread and you wear it down to 2mm tread......)

The only losses you'll get are aerodynamic (via increased tyre width) and frictional due to tyre compound. Stickier / sportier low profile tyres will have higher rolling resistance, but then (as it says on the box) they ARE stickier.....up to you to decide what you want.

If you stick with the other VAG standard of 205/55/16 you'll affect the aerodynamics by a smaller amount, and you are more likely to get an "economy biased" 55-series tyre than a 50-series tyre (if you choose to go down that route).

225 width will give less grip in the wet than 205.
 

gearhead

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Joined
Jan 17, 2001
Location
Weirton, WV (close to Pittsburgh)
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2001 Golf
I have narrowed the selection between the stock size with the stock tires on 5-spoke, GLS optional alloy wheels (Golf) vs aftermarket 205/55/16. Decisions decisions. Anybody have these rims for sale?

Any recomendations on a good, long tread life 205/55/16 tire (mainly for looks, handling secondary benifit--I like the Audi TT style rim).

Thanks for the great information and experience insight.
 
4

4wheeldrift

Guest
2Green, 17s are actually not the hot ticket for Auto-X. They are toooooooooo heavy. Better off staying with 16s on A4s and 15s on A3s. 17s and 18s (and anything bigger) are mainly for looks and impressing the kids with the loud stereos.

I run 205/55-16s on my '01 Golf. They are hi-performance tires, Bridgestone RE-71. I lose about 2-4 mpgs. Part of this is no doubt due to the extra enthusiasm I am driving with now that I have tires I have confidence in. The all-season POS OE tires are of no value to me and certainly did not earn my trust.
 

Kenbob

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Sep 7, 2000
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God's country (Texas)
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2010 Audi TDI
I went from a consistent 42 mpg down to a consistent 38 mpg after upgrading to 16" wheels and 205/55-16 Goodyear RS-A's. The brand and model tire will make a diffence also. The Goodyear's have a very square shoulder (which makes them look wider on the car) compared to Michelin's. This probably effects mileage. After these wear out, I'll probably try Michelin's to test this theory.
 

VelvetFoot

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Sand Lake, NY
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NB, 2000, Yellow
I've gotten a high of 58 mpg and gone over 900 miles on tank of fuel in my '00 Beetle...with 16" wheels and non-aero body. Others NB'ers have as well.
 

meshplate

Well-known member
Joined
Mar 27, 2001
Location
Berkshires, MA
My experience is that the stock ContiTouring Contacts really are bad. No grip and they squeal at ridiculously low speeds especially on very smooth tarmac. Suspension is also way too soft for anyone except old ladies used to caddies. The car also does a flipper teh dolphin act on highway undulations and bottoms way too easily on bumps. But that is another story.
 

TDIMeister

Phd of TDIClub Enthusiast, Moderator at Large
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Originally posted by 4wheeldrift:
2Green, 17s are actually not the hot ticket for Auto-X. They are toooooooooo heavy. Better off staying with 16s on A4s and 15s on A3s. 17s and 18s (and anything bigger) are mainly for looks and impressing the kids with the loud stereos.
<font size="2" face="Verdana, Helvetica, sans-serif">A gross generalization. I am aware of BBS, Centerline and Volk among others who sell forged wheels that weigh-in at about 13 pounds for a 17 wheel, far, far lighter than most 15- and 16-inchers. As for looks, OK I might grant you that for the majority of cases but not always.
 

spoilsport

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Joined
Oct 3, 1999
Location
Houston TX
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2000 Golf GLS Silver (Sold). 2005 Jetta TDI Wagon Tiptronic (daughter's)
I have a different question as I have no intention of upgrading my 15" Avus wheels. At 45,000 and an UPSolute chip, my stock Michelin Energys are shot. Those babies can be quite expensive, and I'm wondering how much mileage I'd give up going to something like Yoko AVS-DBs? Also, what about the Energy's up front with whatever in the back ?


Thanks

[ April 19, 2002, 15:05: Message edited by: spoilsport ]
 

gearhead

Veteran Member
Joined
Jan 17, 2001
Location
Weirton, WV (close to Pittsburgh)
TDI
2001 Golf
update to thread:

Montreal II with 205 55 16 Continental CH 95, noticed a decrease of 1-1.5 mpg (70% hwy/30% city) in 6000 miles. Handling is much improved, road feel namely. It was worth the 'sacrifice' in MPG for me.
 

Derrel H Green

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Joined
Jun 2, 2002
Location
Murrieta, California
TDI
An '05 MBZ E-320 CDI (W-211) replaced the '10 TDI JSW
Originally posted by spoilsport: I have a different question as I have no intention of upgrading my 15" Avus wheels. At 45,000 and an UPSolute chip, my stock Michelin Energys are shot. Those babies can be quite expensive, and I'm wondering how much mileage I'd give up going to something like Yoko AVS-DBs? Also, what about the Energy's up front with whatever in the back ?


Thanks
<font size="2" face="Verdana, Helvetica, sans-serif">


Go to the Tirerack comparison and punch in:

Bridgestone Potenza RE950 - Size 195/65HR15 $70

Yokohama Avid H4 - Size 195/65HR15 $55

And the

Michelin Energy MXV4 Plus - Size 195/65HR15 $115

You'll be surprised at the results. Let that be your decision.


Keep the same brand tires front and rear, but that's just MHO.


Don't let a total of $60 stand in your way of getting the best tire.


 

cdenton

Member
Joined
Sep 10, 2002
Location
Minneapolis
Sounds like you made a decision. But remember if you have a stock suspension you probably don't want to go too sticky on the tire. I found it really brings out the lack luster stock suspension. So then you will want to spend a little more $$$. I'm still looking for the best setup.
 

RattlenHum

Veteran Member
Joined
May 4, 2001
Location
.
Great deal at the local TireMaster on a set of Yong Shung (sp?) EcoTechnic3. $52/tire for 205/55 16. The tread pattern looked similar to the Avid H4.
 
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