The sport edition wheel TX8 is cast aluminum, whereas your OE wheels are low pressure cast aluminum. Low pressure is lighter wheel, yet denser for strength. In general, the 19" is wider, more tread on road=less mpg. The 19" will handle better. The 18" will get better mpg, no doubt.

 

I am not a machinist so I don't really know the difference, but you are saying that the 19" is lighter when it is heavier? Maybe you mean density per specific volume, but the overall wheel at 19" has more metal in it and weighs a good chunk more.

The difference between a 18" @ 255 and 19" @ 265 is only 3.8% whereas I am seeing nearly a 10-15% increase in MPG. The overall weight of the wheel/tire combo is playing a part here.

 

super curious as to what kind of mpg i can get with my 17 winter set. Still waiting on tires. I think a big part of it will be unsprung weight and what kind of driving your doing. The lighter wheels will probably net you better MPG in the CITY and the other's almost the same on the hwy. But I haven't had a chance to test that theory yet.

 

Please reply back when you do.

I do mostly highway miles, nearly 100 a day. So I don't that theory is really true 100%. I think the weight make a bigger difference for starts, but even just keeping wheel running requires less power when they are lighter.

Still looking for the weight specs on the wheels.

 

So I think I am getting that the low-pressure cast is stronger such that it can be made lighter as less overall material is needed for the same strength.

 

Lighter is ALWAYS better for mpg purposes. And by lighter I include the tire also since it makes little sense to shave a few lbs off the wheel and add it back to the tire.
The reason is this: It takes two types of energy to make a tire go down the road - translational energy (like the push to make a hockey puck start moving) and rotational energy (what it takes to make a wheel go around WITHOUT contact with the ground. Both types added together have to be supplied by the motor. That is why it is often said unsprung weight costs twice the energy of 'regular' sprung weight because a big part of unsprung weight is rotational in nature.
The rotational energy needed is proportional to the rotational moment of inertia and THAT is heavily dependent on the amount of mass close to the rim. Example, a flywheel stores rotational energy and is designed with a lot of mass as close as possible to the rim. Ideally, the OPPOSITE should be true for the tire/wheel combo designed to save energy.
All this is why, for mpg purposes, it is vital to avoid changes in speed when driving. It also explains why steady freeway driving is always better than in town driving where nearly constant accelerations and decelerations are necessary even though aerodynamic drag is lower - a lot lower - at slower speeds.
It is therefore no surprise that, given that the winter wheel set is lighter, your mpgs are significantly better. If the handling, traction, ride and tire wear are acceptable to you, keep a light weight set on in the summer too!

 

I have heard radio commercials for a tire retailer that say if you carry an extra 100 pounds around in your vehicle it costs you one or two percent extra fuel. While I may be wrong, I doubt that changing wheels has had much real difference on your fuel use... the four to five percent difference is more likely the computer thinking you travelled further than you really did because of a smaller tire rolling diameter.

 

Another factor, which I didn't mention is the rolling resistance. All tires differ in the amount of 'push' it takes to make the tire roll at the same speed, with the same load, over the same road, under the same conditions. Rolling resistance is poorly documented for passenger car tires but is a really big deal for truckers (as in 18 wheelers). The fuel savings between a tire rated at say 95 and another rated at 105 is enough to pay for a complete set of tires in an amazingly short time - certainly before the tires wear out! There are lots of sources that give the rolling resistance rating of truck tires but very few, if any, for most brands and models of passenger car tires. For truck tires there may be large differences [same size tire] between different models of the same manufacturer.
I mention this because it is another possible factor explaining your mileage increase.
A smaller tire circumference ie more revolutions per mile - also makes the mpgs look better. TireRack publishes pretty good data on the revs/mi for a lot of the tires they sell. Look it up there to find out how much difference that cam make in your case. TireRack also has a good write-up on why its better to use revs/mi than just tire circumference.

 

The smaller RIM would have the same OVERALL diameter than a large rim due to the Smaller rim having a higher rubber profile. All your changing is the size of the rim. your going from say 20" 40 profile tire to a 17" 65 profile tire

 

SamTrooper - Agreed, changing the wheel (rim) size doesn't necessarily mean the rolling diameter of the tire has changed. However, there is usually a small difference between wheel sizes and tire width/profile combinations. Heck, even tire inflation pressure changes the rolling diameter. Because of this, I was wondering if the original poster, CTTouaregTDI, had looked at this as the reason for his (apparent) improvement in fuel economy.

 

Your probably onto somthing with the Width of the wheel impacting fuel economy. A narrower wheel would fare better I imagine.

With your theory, if rolling diameter as you state were impacted with inflation you would then notice an artifical increase in fuel economy with your tires deflated. ( because your overall diameter is shorter and the wheel turns more)

This however, is opposite to what would happen in real life, as with a deflated tire you have increased surface contact and more friction. This impacts fuel economy more than the height. An (over)inflated tire simply has less friction contact with the road leading to better mileage.
Vw tends to use a standard 29" rolling diameter and your actual rim size shouldn't really change that at all.

I've got the 20"ers and 17's I haven't had a chance to put the winters on yet because they're backordered. We'll see if there's really any difference.

 

i wieghed my 18" wheels from my 2011 touareg and they were 62 lbs per wheel/tire set. When i stepped up to 20" wheels i went with Victor equipment wheels for looks and construction.

my 20" wheel/tire combo was actually .5 lbs lighter than my 18's. Better manufactured wheels and lighter tires made the difference.
I love my 20's and have not paid any penelty for installing them over the 18's

IN the end lighter is better when it comes to rotating mass. If you search around and even call the manufacturer of a wheel they will give you the actual weights. for tires i just use tirerack as a reference as they have tire weights in the "specs".

One reason i would never go with chrome.. real chrome wheels weight signifigantly more than cast aluminum wheels.. as much as 10lbs more per wheel. that really taxes your mpg , acceleration and DECELLERATION (braking).

I was surprised though to find that 18" factory wheels were not lighter than a good set of 20" after market wheels that are 2" wider....

 

I'll be very curious to weigh my 19"s to find out the real weight. I am guessing high 60's, but my home scale is off a bit so hard to get something accurate. Just put them on and won't have the time to take them off till next year sometime. I really do like the look of the Everest rims.

I was looking at the Victor rims myself. Found this 18" rim which is really nice looking but can't seem to find a weight spec. I e-mailed Victor about it and waiting for a reply.
18x8 Victor Turismo Silver Wheels

The only problem now is factoring in the cost of changing the rims. Even at a 10% improvement in MPG, @ 20k miles per year that would be a savings of about $500 a year. It would take about 4 years (assuming $2000 for wheels and tires) to recoup the cost on a new set of wheel and tires. In those 80k miles I would likely go through two set of tires minimum which would be closer to $3,000 and 6 years to recoup. That's of course not factoring in how much I can sell the 19"s for.

When you follow that logic, trying to save a few miles per gallon just doesn't seem worth it. At the very least it seems to make sense to go through the 19" tires before making the change.

 

I'll be very curious to weigh my 19"s to find out the real weight. I am guessing high 60's, but my home scale is off a bit so hard to get something accurate. Just put them on and won't have the time to take them off till next year sometime. I really do like the look of the Everest rims.

I was looking at the Victor rims myself. Found this 18" rim which is really nice looking but can't seem to find a weight spec. I e-mailed Victor about it and waiting for a reply.
18x8 Victor Turismo Silver Wheels

The only problem now is factoring in the cost of changing the rims. Even at a 10% improvement in MPG, @ 20k miles per year that would be a savings of about $500 a year. It would take about 4 years (assuming $2000 for wheels and tires) to recoup the cost on a new set of wheel and tires. In those 80k miles I would likely go through two set of tires minimum which would be closer to $3,000 and 6 years to recoup. That's of course not factoring in how much I can sell the 19"s for.

When you follow that logic, trying to save a few miles per gallon just doesn't seem worth it. At the very least it seems to make sense to go through the 19" tires before making the change.

Yea unless you get a smoking deal on wheels...I would wear out the OEM's
19's are expensive though. i didn;t change my wheels for the mpg gain, i changed them for the style and just happen to get a gain also..

 

Just weighed my 19" Everest / Pirelli Scorpion combo and I was shocked; 71-72 lbs. The Pirelli's are listed at 36lbs so that leaves 35-36 lbs for the wheel.

 

Dont forget the air. 35psi is dense and justify's much of that extra weight.

 

I'm finding this all interesting. I bought my Touareg a month ago in Atlanta and brought it back here to Western New York. The OEM tires (275 40 20)were too worn out to drive them back north. I called TireRack for their recommendation on winter tires and wheels and they said go with 18"wheels and put a package together and I had it sent to our son in Atlanta. When I got there we put the winter wheels on and I drove it home. I noticed right away that the speedometer and the speed on the gps were off by 4mph. The car registered 77mph and the gps read 73mph. I am looking forward to putting the new tires on the OEM rims. I was surprised that there was a 4 mph difference. I did inflate the tires to the recommended pressure (39 front and 49 rear). It will be interesting to see what happens when I get the original size back on in relation to mph and miles per gallon.

 

Go to TireRack and look up the revolutions/mi for the tires you bought, then compare that with the ones that came off. If the first number is very much smaller than the second, that would explain SOME of the speedo error you noticed. However, keep in mind that it is a German design requirement that the speedometer be designed to NEVER read less that the actual speed even with the largest size tires that can be put on the vehicle. SO... speedos on german cars always read high.

 

Buyer beware?

I am looking for rim s for winter tires and was thinking about the Sport edition Cup 4 or TX8 18" rims. Then I saw this online:

The Top 5 Toughest Aftermarket Wheels

Needless to say I am having second thoughts

John

 

I am looking for rim s for winter tires and was thinking about the Sport edition Cup 4 or TX8 18" rims. Then I saw this online:

The Top 5 Toughest Aftermarket Wheels

Needless to say I am having second thoughts

John

This package for sale has very true wheels and tires. It's snow, but you'd think it's regular as its quiet and smooth even at 90mph.

 

I agree that the Sport Edition rims are total junk. I had a bent one and I don't even remember hitting anything that would've done it.

I am actually talking with a VW dealer about ordering the VW OEM Sima 17" wheels for the Touareg for snow. I can get a pretty good price (although not cheap) and they are designed especially as winter wheels.

 

I agree that the Sport Edition rims are total junk. I had a bent one and I don't even remember hitting anything that would've done it.

I am actually talking with a VW dealer about ordering the VW OEM Sima 17" wheels for the Touareg for snow. I can get a pretty good price (although not cheap) and they are designed especially as winter wheels.

CTTouaregTDI

I am curious as to why you seem to have given up on the Victor wheels

John

 

I actually hadn't, but this thread is a year old and I hadn't much thought about it until now. But, I've had a few just so-so experiences with aftermarket wheels that have me thinking maybe OEM is the way to go if possible.

 

I was thinking of the odometer error, not the speedometer error.

Another thread points out that with a GPS, the satellites may not calculate the correct distance traveled because roads rarely follow a perfectly straight course. Imagine climbing a winding mountain pass with the vehicle going 50 mph...

I have a GPS on my boat. That adds the river current speed into the equation. If you are navigating upstream into a 3 mph current, the GPS might show 45 mph, but that is your speed over ground. Turn the boat around and...

...too confusing without a brewski to help digest it. I will put some pontoons on my Touareg so I can test my theory with my boat GPS.

An Amphi-treg??

 

Best price I've got is about $360-370 (can't remember which) and when I tried to get more dealer said that was only $10 above their cost - but who knows if that's for real or bologna.

 

This thread has been useful in helping me select a winter wheel package.

My TDI came with 20” Pikes Peak rims with Goodyear Eagle LS2 all season tires. The tires have performed well in dry and wet conditions and have been quiet at speed. However, they have a poor reputation in winter conditions so I decided to get new rims and winter tires.

I am lucky as I can walk to work in 30 minutes (water, city and mountain views) and if I am feeling lazy I can walk two blocks and catch transit and the fares are a fraction of the cost of downtown parking. So my Touareg is not for commuting – just for fun including trips to play in the snow and some long trips that will go through mountain passes. Since there is not a lot of snow in the Vancouver area I decided on 18” rims rather than 17”.

I got a quote for a winter wheel and tire package from a local VW dealer (Dealer A) – and was gob smacked to use an English expression. The quote for OEM Tacora wheels and Pirelli Scorpion ice and snow tires was double what I expected.

I went on line and found a wheel and tire package through the Canadian equivalent of Tirerack for about 40% less. The wheels were Sport Edition with the same Pirellis.

Reading this thread about wheel weight got me thinking. I enjoy the low fuel consumption of my TDI and drive as efficiently as I can so lighter wheels made sense. But:
1. Heavier wheel = more metal = stronger wheel; and
2. Cheap after market wheel is likely gravity cast, whereas the OEM wheel is likely pressure cast and stronger metal = stronger wheel.

One of the lessons I learnt hiking and backpacking in the mountains is to buy good sturdy gear. Not fun stuck on the mountain with the cheapest gear you could find. That plus the comments about the Sport Edition wheels in this thread and the review from the wheel repairer I posted earlier made me avoid the Sport Edition wheels.

I went to a second VW dealer (Dealer B) and got a quote for the same OEM Tacora + Pirelli package. Bingo – 25% less than Dealer A, who wondered how Dealer B can sell below wholesale cost.

Dealer A wheel price Cdn$440. Lowest price I could find on line U$373. Dealer B has not provided me the wheel only cost yet but I will post if I get it.

I will ask the dealer to weigh the 20” Pikes Peak rims and GY LS2 combo when they change.

John

 

Dealer B quotes "The wheels would be $350/wheel plus tax. That is a savings of $90/wheel over MSRP."