Wheel weight vs over all weight.

[UltArc]

Originally Posted by Sven7

That shows that the 14 pound difference between the wheel/tire packages- 15x6" and 19x8.5"- was 2.2mpg over their test, with the smaller wheels being better. The roadholding also drops 0.05g with the skinnier 195 tires compared to 235's.

Also note that the 2.2mpg improvement also equated to 0.2 seconds and 2mph quicker in the quarter mile. Braking 60-0 mph is 4 feet worse with the skinny tires.

The smaller wheels and tires have lower prices, lower weight, better mpg, better acceleration and marginally lower road noise.

_________________________________

Relative to this thread, I will say that if the cars are the same weight, whichever car has less rotational mass will be better for mpg in stop and go situations. Whether the difference is multiplied by 1.5 or 10, you're still going to benefit by reducing rotating mass.

I just realized this test is completely focused on keeping tire diameter the same. To be clear, it does not affect gearing, aka how many axle rotations to travel so far. This was only comparing the rim/tire ratio, keeping them at the same tire diameter.

Something to keep in mind if you are thinking about changing gearing (tire diameter).

[HypermilerAX]

The thing is that the tires do NOT have the same diameter. They even say it : "speedometer error". There is 2% difference and that cannot be disregarded when you're measuring something at 0.1 mpg.

Originally Posted by GreenHornet

If your goal is MPG then you want a light weight, tall, and narrow tire.

Why tall? Because of better rolling resistance? Taller tires are heavier and make worse aero. Big gearing should be done with the gearbox, not the tires.

[mcrews]

Originally Posted by Sven7

That shows that the 14 pound difference between the wheel/tire packages- 15x6" and 19x8.5"- was 2.2mpg over their test, with the smaller wheels being better. The roadholding also drops 0.05g with the skinnier 195 tires compared to 235's.

Also note that the 2.2mpg improvement also equated to 0.2 seconds and 2mph quicker in the quarter mile. Braking 60-0 mph is 4 feet worse with the skinny tires.

The smaller wheels and tires have lower prices, lower weight, better mpg, better acceleration and marginally lower road noise.

_________________________________

Relative to this thread, I will say that if the cars are the same weight, whichever car has less rotational mass will be better for mpg in stop and go situations. Whether the difference is multiplied by 1.5 or 10, you're still going to benefit by reducing rotating mass.

Seven,
I disagree with the application of your comments.
While you are correct about WHEELS
it is important to note that there were staying at the same (roughly)final diameter.

More weight (larger WHEEL) resulted in the poorer mpg.
heck, the 15 inch tire alone weights 26 and the 19 inch tire weights 44!!!!!!

[mcrews]

Originally Posted by HypermilerAX

The thing is that the tires do NOT have the same diameter. They even say it : "speedometer error". There is 2% difference and that cannot be disregarded when you're measuring something at 0.1 mpg.



Why tall? Because of better rolling resistance? Taller tires are heavier and make worse aero. Big gearing should be done with the gearbox, not the tires.

False.
The 2/10% error in size is within the margin of error. If you have followed any of the multiple threads on taller tires, we all agree that you need to be atleast 5% increase to accurately explain the increased mpg.

shoulda, woulda coulda......you paying the bill for new gears?????
MANY members here use taller tires to improve mpg by lowering the rpm at cruise. Please see my threads on my Infiniti Q45 245/45/18 stock to 245/50/18. Same improvement on my KIA Sportage 235/60/16 stock to 235/70/16

Taller tires barely weigh 1 lb more. and do not measureably increase aero.
But I'll Take my proven gain in mpg (along with the other proven result from other members) all daylong over a 'precieved' reduction in aero.

[Sven7]

Originally Posted by mcrews

Seven,
I disagree with the application of your comments.
While you are correct about WHEELS
it is important to note that there were staying at the same (roughly)final diameter.

More weight (larger WHEEL) resulted in the poorer mpg.
heck, the 15 inch tire alone weights 26 and the 19 inch tire weights 44!!!!!!

I don't know what you're on about. I did not insinuate that the OD was notably different. Do we really need to quote and repeat things?

[mcrews]

Sorry....probably came across wrong.....my bad.


(where I was headed was that so many times someone says 'wheels' and means tire/wheel combo.
I was just acknowledging that you were correct in your comments. Hoping that someone else didnt pick it up as impling tire/wheel combo)

[Honda]

Originally Posted by California98Civic

Here is my list of possible wheel swaps for 5th/6th gen Civics like ours, from my car's garage site:

Possible wheel swaps for gearing/weight advantages:
13" Civic VX 8 spoke (higher RPMs but only 9.7 lbs.)
14" Civic HX 8 spoke (approx 11 lbs)
14" Miata 1990-93 cast alloy (12.5 lbs)
15" Mini Cooper R81 Imola 7-hole (12.1 lbs)
15" Mini Cooper R86 star-spoke (15 lbs)
15" Mini Cooper R96 7-spoke (13.8 lbs)
15" Enkei Classic J-speed (14.1 lbs)
15" Prius C alloys (as light as 11.5lbs)
15" Prius C steelies (16lbs)
15" Acura Integra GSR (94-95, 16lbs)
Other size specs: Offset 35-45; bolt patter 4X100; lug size 12mmX1.5

-james

The 13'' VX wheels were the first option that I want to get but I missed couple deals on Craigslist so I ended up buying these instead:

[Sven7]

OP, what are those wheels from? They look nice. 14" or 15"?

Originally Posted by mcrews

Sorry....probably came across wrong.....my bad.


(where I was headed was that so many times someone says 'wheels' and means tire/wheel combo.
I was just acknowledging that you were correct in your comments. Hoping that someone else didnt pick it up as impling tire/wheel combo)

Oh ok I gotcha. You were just clarifying for the 'audience'.

[Sven7]

Originally Posted by freebeard

-- VW uses 4x100 with 12mm bolts, but I'm not sure about the offset. Is the wheel centered on the hub or the lug bolts? I wonder if you held up the one against the other where the interference would be.

I've seen stock Mk1 Rabbit wheels with offsets anywhere from +32 to +45. The 45's tuck a lot. The big difference is the 1mm larger center bore of the wheels- 57.1mm instead of Honda's 56.1mm. VW's are ball seat, hub-centric.

If you're putting VW wheels on a Honda, go for the lowest offset you can find. EG's tuck a lot with factory wheels- I'm considering buying 15x7" +15 wheels for this EG, so you can get an idea of how much leeway you have.

Anyway, that's pretty off topic now, but perhaps it will help someone later on.

[Honda]

Originally Posted by Sven7

OP, what are those wheels from? They look nice. 14" or 15"?

These are 15'' , I believe they are stock from 2002/2003 Civic Si.