it was interesting to read in C&D their article on upsizing wheels. Effects of Upsized Wheels and Tires Tested - Tech Dept. - Auto Reviews - Car and Driver

basically, the bigger, wider 19-inch wheels slowed the Golf down and had less grip than the 18-inch wheels. so does this mean those w/the sport package are slower than the non-sport/AWD?

i've the 18" wheels for the x-coupe, and while aesthetically inferior to the 19", do they offer better performance than the 19s?

 

Yes probably by 0.000000001%.

 

does a 0.000000001% difference give us non-sport/AWD owners bragging rights?

 

It all depends on what you're looking for.

 

you AWD guys can brag about your 0.000000001% advantage and we will brag about being able to put sway bars and other non-AWD mods on our G's, sound fair?

 

I believe bigger wheels have a larger rotational mass (and simply more mass due to the size and lower profile tires needing heavier sidewall) hence the poor fuel economy.

As for poor performance, I think the Golf does not have the cajones to move a larger wheel nor the weight. Wheel size and weight per unit of tread contact is also a part of the math. That is take a rock and place it on water - it sinks since the mass is located on a small cotact patch. Take a boat - it floats and can skim across the wated since the mass is carried across the entire contact patch. Larger wheels are for high speed driving in car that can handle it given the mass to contact patch ratio. The golf is probably too light for the tires they used and hence the poor results.

I am no engineer but am simply using logic to assess...

Flame away...

 

The S has better handling. The collision repairs that X owners pay for make up for the gas. :P

This could be completely wrong, as I'm talking out of my ****.

 

Most of the time, upsizing your rims will obviously result in great rotational mass which may affect the car's overall performance. However, there are rims out there in 19's that are even lighter than the stock 18's or 17's. Don't just judge the rims by its size. Forged monoblock wheels are stronger & lighter than OEM cast wheels.

 

True.

Also remember, that lighter generally is better, but moment of inertia is what really matters. If you get wider tires, likely, the tires are much heavier, and could possibly negate all gains.

 

^ Yes.

Too many factors come into play when trying to compare the advantages & disadvantages of upsizing your wheels.

 

^^
A dyno could tell you the losses

 

 

No because you still have an automatic tranny.

 

what does this mean?

Something wrong with the AWD's?

 

Hmmmm, looks pretty slow to me.