Small wheels versus big wheels - acceleration test and the results
Has any one ever wondered what difference it makes for your acceleration when you change your small OEM wheels with larger aftermarket wheels ??
Well, in the last few days I had the opportunity to test just that.
Perhaps some of you will remember that with my previous NSX (a modified 1994 NSX), I did a similar test with heavy BBS wheels and lighter OZ wheels, all in the same size and using the same tires.
( http://www.nsxprime.com/forums/showthread.php?t=98186 )
Just recently, I aquired a 1998 sebring silver NSX-T in completely stock form with the original OEM 16" front and 17" rear wheels.
I decided to redo the test I done before in the same way and on the same piece of road before I really started modifying my car.
The tests were performed in the same way as before, trying to minimize a much variables as possible.
To measure the acceleration times, I am using a AP22 acceleration meter from Race Technology (http://www.race-technology.com/ap22_2_82.html). This device measure acceleration times using a G-meter with an accuracy of 0.01G.
All acceleration runs were done in second gear and the acceleration measured was from 20 kph to 100 kph. This speed interval was chooses because it can be done in one gear, avoiding the human error that is introduced by shifting into a next gear.
To do the test, I used the following procedure:
- Tape the AP22 to my dashboard so that it is mounted correctly.
- Fill up the gas tank completely
- Drive to the straight stretch of road chosen for the test. (Gave the engine time to warm up completely).
- Start the AP-22, set it up to measure 20kph to 100kph acceleration, and let it calibrate.
- Start driving in 1st gear. As soon as the car is rolling, shift to second and let the car roll forward in 2nd gear at idle rpm without touching the throttle.
- Wait until the car is rolling forward smoothly and with a constant speed. This took about 5-10 seconds.
- Then, press the accelerator down to the floor and let the car accelerate until the AP-22 displays it has finished the acceleration run.
- Bring the car to a standstill, store the data on the AP22, turn the car around, calibrate the AP22 again and do the next run.
- With every set of wheels, this test was repeated about 12 times.
After the first test, the OEM wheels were swapped with the OZ Ultralegger wheels. Then, the gas tank was filled up completely again and the NSX was taken to exactly the same piece of road and the test were repeated using the exact same procedure.
Every wheel and tire was weighed seperately.
First, the weights:
OEM 16" front wheels with 225/45/16 Michelin Pilot Sport tires. Weights were 17.0 and 17.0 kg = total 34.0 kg or 75.0 lbs
OEM 17" rear wheels with 255/40/17 Michelin Pilot Sport tires. Weights were 19.8 and 19.9 kg = total 39.7 kg or 87.5 lbs
OZ Ultraleggera 17" front wheels with Falken FK452 235/40/17 tires. Weights were 18.6 and 18.6 kg = total 37.2 kg or 82.0 lbs
OZ Ultraleggera 18" rear wheels with Falken FK452 265/35/18 tires. Weights were 19.7 and 19.6 kg = total 39.3 kg or 86.6 lbs
Total weight OEM wheels plus tires: 73.7 kg or 162.5 lbs
Total weight OZ Ultraleggera wheels plus tires: 76.5 kg or 168.7 lbs
So, even though the OZ wheels are very light, the larger tires and wheels result in a weight penalty over the stock wheels of 2.8 kg or 6.2 lbs.
Now, for the results.
Acceleration runs from 20kph to 100kph in 2nd gear:
OEM wheels 16/17":
6.14 - 6.01 - 6.17 - 6.10 - 6.07 - 6.13 - 6.10 - 6.07 - 6.14 - 6.16 - 6.16 - 6.17 seconds:
Average: 6.12 seconds
Deviation: 0.05 seconds
Maximum: 6.17 seconds
Minimum: 6.01 seconds
OZ Ultraleggera wheels 17/18":
6.18 - 6.24 - 6.07 - 6.20 - 6.18 - 6.18 - 6.14 - 6.23 - 6.14 - 6.14 - 6.15 - 6.17 seconds
Average: 6.17 seconds
Deviation: 0.05 seconds
Maximum: 6.24
Minimum: 6.07 seconds
Because of the test with the heavy and lighter wheels (BBS and these same OZ's), I did not really expect to see much difference, so I was not really surprised to see that the acutal differences were hardly noticable.
What DID surprise me a bit was the fact that my previous modified car with the 3.0 NA1 engine was appreciably faster than this newer 1998 3.2 NA2 model.
The difference between the two tests is about 0.5 seconds which is about 8%.
Of course, the 1998 NSX-T model is much heavier. Last week, I had the car weighed at with a full tank of gas its weight came out at 1420 kg or 3131 lbs.
My previous car last recorded weight with a full tank was 1345 kg or 2965 lbs.
However, somehow, I expected the increased torque from the 1998 model to make up for the heavier weight. This turn out not to be the case so far.
Here are two picturs of the car, first with the OEM wheels and second with the OZ wheels (the OZ's look better don't you think )
With the OEM wheels
With the OZ Ultraleggera wheels
Now, of course, I can finally start modifying the car. First to remove some of that excess weight.
And yes, I am planning to redo these test again after I have made her loose some weight
Has any one ever wondered what difference it makes for your acceleration when you change your small OEM wheels with larger aftermarket wheels ??
Well, in the last few days I had the opportunity to test just that.
Perhaps some of you will remember that with my previous NSX (a modified 1994 NSX), I did a similar test with heavy BBS wheels and lighter OZ wheels, all in the same size and using the same tires.
( http://www.nsxprime.com/forums/showthread.php?t=98186 )
Just recently, I aquired a 1998 sebring silver NSX-T in completely stock form with the original OEM 16" front and 17" rear wheels.
I decided to redo the test I done before in the same way and on the same piece of road before I really started modifying my car.
The tests were performed in the same way as before, trying to minimize a much variables as possible.
To measure the acceleration times, I am using a AP22 acceleration meter from Race Technology (http://www.race-technology.com/ap22_2_82.html). This device measure acceleration times using a G-meter with an accuracy of 0.01G.
All acceleration runs were done in second gear and the acceleration measured was from 20 kph to 100 kph. This speed interval was chooses because it can be done in one gear, avoiding the human error that is introduced by shifting into a next gear.
To do the test, I used the following procedure:
- Tape the AP22 to my dashboard so that it is mounted correctly.
- Fill up the gas tank completely
- Drive to the straight stretch of road chosen for the test. (Gave the engine time to warm up completely).
- Start the AP-22, set it up to measure 20kph to 100kph acceleration, and let it calibrate.
- Start driving in 1st gear. As soon as the car is rolling, shift to second and let the car roll forward in 2nd gear at idle rpm without touching the throttle.
- Wait until the car is rolling forward smoothly and with a constant speed. This took about 5-10 seconds.
- Then, press the accelerator down to the floor and let the car accelerate until the AP-22 displays it has finished the acceleration run.
- Bring the car to a standstill, store the data on the AP22, turn the car around, calibrate the AP22 again and do the next run.
- With every set of wheels, this test was repeated about 12 times.
After the first test, the OEM wheels were swapped with the OZ Ultralegger wheels. Then, the gas tank was filled up completely again and the NSX was taken to exactly the same piece of road and the test were repeated using the exact same procedure.
Every wheel and tire was weighed seperately.
First, the weights:
OEM 16" front wheels with 225/45/16 Michelin Pilot Sport tires. Weights were 17.0 and 17.0 kg = total 34.0 kg or 75.0 lbs
OEM 17" rear wheels with 255/40/17 Michelin Pilot Sport tires. Weights were 19.8 and 19.9 kg = total 39.7 kg or 87.5 lbs
OZ Ultraleggera 17" front wheels with Falken FK452 235/40/17 tires. Weights were 18.6 and 18.6 kg = total 37.2 kg or 82.0 lbs
OZ Ultraleggera 18" rear wheels with Falken FK452 265/35/18 tires. Weights were 19.7 and 19.6 kg = total 39.3 kg or 86.6 lbs
Total weight OEM wheels plus tires: 73.7 kg or 162.5 lbs
Total weight OZ Ultraleggera wheels plus tires: 76.5 kg or 168.7 lbs
So, even though the OZ wheels are very light, the larger tires and wheels result in a weight penalty over the stock wheels of 2.8 kg or 6.2 lbs.
Now, for the results.
Acceleration runs from 20kph to 100kph in 2nd gear:
OEM wheels 16/17":
6.14 - 6.01 - 6.17 - 6.10 - 6.07 - 6.13 - 6.10 - 6.07 - 6.14 - 6.16 - 6.16 - 6.17 seconds:
Average: 6.12 seconds
Deviation: 0.05 seconds
Maximum: 6.17 seconds
Minimum: 6.01 seconds
OZ Ultraleggera wheels 17/18":
6.18 - 6.24 - 6.07 - 6.20 - 6.18 - 6.18 - 6.14 - 6.23 - 6.14 - 6.14 - 6.15 - 6.17 seconds
Average: 6.17 seconds
Deviation: 0.05 seconds
Maximum: 6.24
Minimum: 6.07 seconds
Because of the test with the heavy and lighter wheels (BBS and these same OZ's), I did not really expect to see much difference, so I was not really surprised to see that the acutal differences were hardly noticable.
What DID surprise me a bit was the fact that my previous modified car with the 3.0 NA1 engine was appreciably faster than this newer 1998 3.2 NA2 model.
The difference between the two tests is about 0.5 seconds which is about 8%.
Of course, the 1998 NSX-T model is much heavier. Last week, I had the car weighed at with a full tank of gas its weight came out at 1420 kg or 3131 lbs.
My previous car last recorded weight with a full tank was 1345 kg or 2965 lbs.
However, somehow, I expected the increased torque from the 1998 model to make up for the heavier weight. This turn out not to be the case so far.
Here are two picturs of the car, first with the OEM wheels and second with the OZ wheels (the OZ's look better don't you think )
With the OEM wheels
With the OZ Ultraleggera wheels
Now, of course, I can finally start modifying the car. First to remove some of that excess weight.
And yes, I am planning to redo these test again after I have made her loose some weight
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