QuestionMr. Brandt, you may not be the one to answer this question but I'll give it a shot.I recently bought a 2005 Hyundai tuscon 4 wheel drive SUV and so far I love it. But I have a question about the 4 wheel drive. The dealer told me that the four wheel drive only works at speeds 20 mph or less. The owner's manual coincides with this and goes on to say that at 30 mph the 4 WD is at 50% effective and at 40mph - no longer effective. The dealer tells me this is true with all 4WD vehicles. I looked in the owners manual of my husband's 4x4 dodge ram and it doesn't say anything of the sort. Is this true that 4WD only is effective at 20 mph or so? Thanks for any info you can give me.
AnswerGrace,
First of all, it sounds like the Hyundai does not have true 4-wheel drive, but an all wheel drive, or a full-time 4-wheel drive system of some type. In this case, you probably do not have a transfer case. this indicates that the all wheel, or 4-wheel drive in this vehicle is intended to work all the time with some speed limitations.
Your system sounds more like a 4-wheel assist, or traction control than a 4-wheel drive. I'm sure that the dealer is correct in the operation of your car, but he doesn't know very much about a true 4WD vehicle.
Any true 4-wheel drive vehicle, such as your Dodge, should not be operated on any hard surface such as asphalt in 4-wheel drive, unless you are in snow or ice (possibly heavy mud.) This is why they have a transfer case, and can be shifted in and out of 4-wheel drive. A true 4WD vehicle, when shifted into 4WD is driving both the front end, and the rear end at the same time regardless of the speed you are going. Some 4WD vehicles, such as my Grand Cherokee, have an additional set of gears in the transfer case that allows for 4WD operation on hard surfaces. This is called "full-time." Vehicles that have this, also have a part time, or locked position for off-road, or snow driving.
I hope this will give you a small understanding of how 4-wheel drive works.
Carl
