Your truck has a real 4WD system meaning you DO NOT want to use 4WD on pavement. It will bind up and if enough traction is available, something will break. Use it only in low traction situations.FS552 said:Can you all tell me the when is the best time to use 4HI, 4LO.
Yes, GM has named their push button 4WD system "Autotrac"Also is the Auto 4WD drive the same thing as the auto track you all were mentioning earlier?
Unlike other brands, 4Hi can be engaged at any speed. I've engaged mine doing 70mph after encountering snow and ice in the mountains of New Mexico.Oh and should I stop before I engage in either 4hi or 4lo? Or can I just push the button while i'm driving. If not, well I already did it once LOL.
The best part! Normally the transfer case enters 4WD followed by the front axle engaging. Auto 4WD, engages the front axle first and in milliseconds uses clutches to engage the output of the transfer case if a speed difference is encountered between the front and rear wheels. You can drive in Auto 4WD on any surface at the penalty of slightly diminished fuel economy. It really shines when road conditions are changing like rain, snow and ice.and Auto 4WD
Sorry to politely disagree. I worked for GM up through 1999. I spent two day of training on the autotrac system and it works just as I discribed. GM did offer an "all wheel drive" on the smaller trucks/suvs but not on the full size. Quoting from the training manual:Big Dave, auto trac is not just push button 4x4 it is all time 4x4 that has a computer control telling it which wheel to send the power too when there is slippage including front wheels. I have a similar system on my ford and it is all time 4x4
Yes and No. The Auto 4WD function works by engaging the front axle. At this point it is working like your Ford in 2WD. No power is getting to the front axle but it is turning. Once the Autotrac computer sees a difference in RPM between the front and rear (like 15rpm difference) it know to engage the 4WD transfer case clutches. GM claims the clutches in the transfer case can be locked up in as little as 200 milliseconds. The transfer case module then cycles the clutches ever 50 millisecond to release pressure on the clutches to see if 4WD is needed. If it determines there is no more slip between the front and rear wheels it releases the clutches completely basically returning it to 2WD mode except for the front axle being engaged.The only thing that I was saying about the chevy auto track is that once you push that Auto 4wd button (autotrac) it is in AWDand the front and rear wheels will be getting power at a computer/traction decided level and this is different from 4HI.
Tell me about it. It took $44.00 to fill up the suburban yesterday. I ententionalyArgo said:BTW my fuel mileage does stink.
Tell me about it. It took $44.00 to fill up the suburban yesterday[\quote]
You should have bought a '92-'99 model Suburban. 42 gallons of fuel. It takes about $70 to fill mine up.
Turned out to be 13.65 miles per gallon. Does that sound right bigdav160?[\quote]
Mixed driving with the A/C on? Then yes. Remember those truck are as aerodynamic as a brick and quite heavy. Just for fun check the EPA fuel economy averages for those V6 midsize SUV's. They are the same as your full size V8 powered SUV.