I spent yesterday afternoon helping my son's 1st grade class learn math. When it was over, he decided to ride with me rather then take the bus. on the way back to our house, we passed one of my favorite spots for testing acceleration and braking of tires. It is an access road that leads from the main road to the train tracks. It is also used as parking for the Little League fields, so it is quite wide.
The road was covered in roughly 6 inches of fresh powder, and the temperatures were in the single digits. Since I have been writing a rally, I had the rally computer still in the car. The computer I run is an Alfa Pro. It only measures distance, but it does it to 0.001 miles and is adjustable. It also has an often handy little feature for measuring performance. It will measure 0-30 mph, 0-60 mph, and 1/4 times along with 1/4 speed.
I have put the pickup for the computer on the undriven, front left wheel, so wheel spin is not considered when making measurements. The computer was adjusted to statute miles, and the last check (2 days ago) showed it reading 1.002 miles per measure miles.
Since I had the equipment, i decided to see how fast the Hakka-2s did 0-30mph. (There is no room to get to 60 mph.) After six timed runs, I took my son home and we changed to the studded Hakka-4 snow tires. The the test were done in loose, snow, the effect of the studs does not need to be considered.
The Hakka 2 tires have 3 seasons on them. The Hakka 4 tires have 1 season. The tread depths are roughly equal.
The car used to do the testing was my '94 Volvo 960 Sedan. This car has three transmission modes: Economy, Sport, and Winter. Economy and sport are basically the same except that they differ in upshift point. In Winter mode, the transmission starts out in 2nd gear instead of first. This is supposed to produce less wheel spin.
The car is also equipped with an automatic locking differential that locks when it detects wheel spin between 5 and roughly 30 mph.
The times from the runs are shown below. The rally computer only starts measuring when it detects the car moving, so initial wheel spin is not considered. The times are seconds for 0-30 mph.
- Sport: 14.5, 9.1, 11.1
- Winter: 13.1, 17.1, 11.8
- Sport: 6.5, 10.5, 7.4, 8.3
- Winter: 7.4, 8.9, 9.3
Looking at the data, the first thing that strikes you is that once the car starts moving, Sport mode is actually faster in acceleration.
The more interesting piece of information is that the slowest time for the Hakkapeliitta 4s is faster then all but one time for the Hakkapeliitta 2s.
I am hoping to post a short video of some of the test runs a little bit later.