gtr902

Hello I'm new to this forum and a new owner of IS250. As I'm reading through the manual, I see there's only little to nothing that talked about the feature of TRAC button. So I'm wondering what does this TRAC button do? and is it enable when you see a symbol on dash or disable? Also if TRAC button improves traction, then what is the funtionality of the SNOW button? man i'm really confused!!

The Chad

TRAC disables use of the traction control system, at least until you hit a certain speed (from my understanding). If the system detects wheel spin, it reduces engine power to attempt to regain traction. VSC uses the brakes along with the traction control to stablizie the car if it skids to keep the car going in the direction the driver intends.

Snow mode adjusts the throttle control so that light presses of the throttle isn't as instaneous of a jolt as it would in PWR mode. Also, I believe the car starts in 2nd gear instead of first, again, as a method of maintaining traction.

So to summarize the difference. TRAC is an after-the-fact response to a loss of traction (it has to occur before it engages), and SNOW is pre-cautionary. It's there to help not lose traction. Most of the time, you don't want to drive in SNOW, but you'll want to almost always leave TRAC on just in case the unexpected happens.

gtr902

thankz appreciate it

Gernby

iTrader: (1)

Snow mode doesn't just effect throttle response. It also changes the behavior of the transmission. It won't downshift as much when you increase throttle. I actually kinda like Snow mode on the highway sometimes since it smooths out my pulsating foot.

I haven't really figured out TRAC yet myself. I've done lots of throttle punches from a stop with / without TRAC, and with / without TRAC and VSC. If I just disable TRAC, then I seem to get a bit more wheel spin before VDIM cuts throttle, but it still does cut throttle even in a straight line.