I have a 2005 GMC Savana , 2500 model with 4.8 V8

It has the Trailer tow button , but I am not sure what it does !

and is it good or bad to use it all the time around town ?

Thanks for your advise

 

changes the shift strategy...delays upshifts the only downside would be fuel consumption.

 

It's for towing. It's good to press it when you tow. When you don't tow, you turn it off.

 

It also may be good if you're close to a full load. Weight is weight, regardless of whether it's behind the van, or in it.

 

Thanks for your replies , are the shift points the main thing ?

does it send more fluid to the cooler or is that the same with Tow on or off ?

 

It keeps the transmission from shifting more than it should, or in lower gear on hill's ect.

 

To extend the life of any transmission is to keep the fluid temps cool... there are many ways to do this.... but i can honestly say ive towed many things with my van in the last 2 yrs and I dont use the Tow button.....why well I dont need it.... if you monitor the trans temps like I do you will see that the temps increase when you use it I sure dont want to add the extra heat when its not needed....i sure caint imagine why any one would use it with the stock equipment....
I personally would recommend upgrading any stock express or savanna or in my case GMC Express... lol inside joke

 

It does not help with engine braking on grades. You need to use the shifter to kick it out of OD or the van will run away on you. Some of the newer vans do have engine braking as an option but I don't know which years. I would be game for reprogramming my 2004 if that was possible.