Cat 475 vs 550 vs 625

Will CAT tune it higher than what the trans is rated for or will I have to go to someone outside of

 

No cat is not likely to tune it over the weakest rated parts. But I wouldn't have a dealer tune it anyway. There are much better options for tuning outside the dealer

 

What are those options? Or we can’t mention it here? Lol

 

Custom tune. There's lot of people that have them or do them. Facebook cat engine masters has some good guys

 

Compounds are great with proper tuning but somewhat harder to maintain. More places to leak and burn out in exhaust path and much harder to change thermostats and the like.

 

Cat dealer will put the latest and greatest low NOx file in it anyways. If you're pre-low NOx I'd leave it alone over having a dealer tune it.

 

Pre-emissions: KTA 1150 Cummins. Cat 3408 or 3412. Detroit 12V-92TA My choice for cost, reliability and easy power up to 800 HP is the KTA 1150. For power up to 1000 HP and awesome coolness I'd pick the 3412.

 

Kinda old conversation, but having driven a lot of acerts (and other cat's), I figured I'd weigh in on this since nobody has mentioned certain details, the 475 has no advantage on the bigger power versions as far as fuel mileage. Internally the 475/500/550 engines are mechanically identical, the difference in power is 100% in the tune, and all 3 power levels are readily available in all factory 475 to 550 programs, simply by plugging in with Cat ET and changing the power setting.
Unfortunately that means that the 475hp setting is actually the least efficient setting available, and even tho it's the most fuel, the 550hp setting is actually the most injection advance as well, which makes it the most efficient.
Speaking from experience, the difference is not huge (aftermarket tunes are usually substantially better, when done properly), but when you track every tank like I do, it's definitely noticeable.
It's been a while since I drove any of our cats with the 475 setting, but as I recall, the difference was roughly high 3.xxmpg to almost 5 (mid to high 4.xx).