I have the 1745 tuner. I usually just run the 87 octane tune. I use it mainly, not for more HP, but to adjust trans shift pressure and shift points.

So when I go to install the 87 tune, it askes if I'm going to be towing over 4000 lbs. I answer yes, then it says to use the 91 Tow tune.

Why is this the case??? The way I understand it, the 87 tune really doesn't do much in the way of 'tuning' the engine, and therefore EGT's shouldn't be any higher... EGT's are one of the main concerns when towing using a 'performance' tune, right? In addition to that, the shift pressure that I use (stock + 12psi) is still lower than the 91 Tow tune.

So, should I be ok towing my 5500 lbs travel trailer using the 87 tune? I'd just hate to have to switch back to stock every time I want to tow (I am NOT going to pay for premium fuel right now)...

 

I wouldn’t use anything but a tow-preferred tune or the stock tune to tow 5500 lbs. That’s an 87-octane performance tune in the 1745, it’s not meant for towing. Premium fuel is only 20¢ a gallon more; you burn a valve it’s going to cost ya

 

Yeah I know, but if I go with Premium than I have to face the fact that I will be paying over $3 a gallon...
If I stick with 87 octane, then I'm paying UNDER $3 a gallon

Just kidding... I get your point...

 

btt

 

This is pretty simple, I'd say just follow those instructions and do as the manufacturer says. They know what the EGT's end up at and that is one of the primary factors governing how much weight you can tow with a certain tune setup.

I suggest that you follow the instructions and not attempt to tow 5500 lb on that tune - if you are going to tow darn near a TON more than that tune is rated for, bite the bullet and bump up to the right tune - premium fuel is a lot cheaper than burned exhaust valves, etc.

Good luck & enjoy your Labor Day weekend!