CAMMIN03'

iTrader: (1)

I have a 2003 silverado 5.3.... I dynoed the other day and the guy said put your tow haul on.... does this effect anything or should i have not put it on??????

I think you all konw this all ready but its a Automatic....

v8

iTrader: (10)

well when i dynoed my 4.8 along time ago i did a comparison and with it on it dynoed 10 hp less and tq was down as well just cant remember how much. dynoed with it first and without it last.

elite22xl

iTrader: (1)

the only thing the tow haul on the trucks do is change the transmission gearing so the final drive is a 4.10 rather then the 3.83 or whatever it is. just helps for towing. i would imagine that it would dyno less with the 4.10 ratio in the trans. this is just from what i understand. not sure how true it is

Chase71Z28

The tow haul setting on the truck does not change the gearing in the trans. What this button does is just change the shift point of the trans. You can see this in an editing program. It is under the performance setting. When tow haul is engaged it makes the trans shift later so it is easier to tow a trailer. It is easier to tow a trailer b/c the motor is higher in the rpm.
Chase

badpewter-z

iTrader: (4)

exactly tow/haul is basically a mild pushbutton shift kit
holds the gear longer in the rpm brfore shift
little more pressure and a little quicker

01_SuperSlow

iTrader: (7)

Exactly.

marc_w

Yeah, it's pretty much already covered here, but my '04's tow-haul sounds a little different.

WOT shift points are both set at 5,200..... vs 5,600 for the 1-2 and 5,200 for the 2-3.

The upshift downshift parameters are changed so that shifting is "more consistant." (my wording from what I read in my owners manual).

I found that my shift pressures were actually REDUCED in tow/haul. Not by a lot, but in all of the part throttle cruise ranges you'd typically be in.

That's all...

B18B1LS1

iTrader: (12)

My '03 5.3 does the same as marc_w stated with the tow/haul on.