What about reliability, will I shorten the life of my gearbox by using xHP?
None of the setups will have a general detrimental effect on the life of transmission components. Not the TCU, not the shafts, not the clutches. Remember that automatic transmissions are highly complex units, with several hundred components inside. Some of these components (such as clutches) are designed to wear through use. Your driving style and proper maintenance have the greatest impact on the life of transmission components.
Follow these simple rules:
Allow the transmission to warm up each time you drive before you apply heavy throttle. You will notice a certain amount of slippage during the warm-up period, which is designed to bring the oil inside up to operating temperature more quickly. As a general rule, your transmission will take about the same amount of time to warm up as your engine oil.
Don't "pump up" your car when starting from a standstill with the brake/throttle applied at the same time.
Change your transmission oil regularly. (approx. every 50k - 75k miles) BMW does not want you to do this, but ZF does. Trust ZF, who built this transmission.
Do I need a break-in period?
We recommend a running-in period of about 50-75 miles without wide open throttle, with different speeds, load scenarios and gearshifts, to allow the transmission to adapt to the new software as quickly as possible.
This running-in phase is only recommended after the first xHP flash and is not required for subsequent flashes, such as map changes or different custom settings, etc.
I just flashed my transmission, but the shifts are bad.
Your transmission may behave strangely immediately after flashing, e.g. starting in 3rd gear. This problem should resolve itself within a few hundred metres of driving.
The transmission has extensive adaptive algorithms to maintain shift quality throughout the life of the transmission, even with heavily worn clutches. The adaptive algorithms are very sensitive to abrupt changes as they operate within a narrow window. Shift quality can therefore suffer in the first few hundred miles after an oil change, a change of transmission hardware or, as with xHP, a change of TCU software.
Don't overload your transmission during this adaptation period. The best way to acclimatise your transmission is to drive it normally in D mode with lots of different speeds and shifts.
We DO NOT advise anyone to delete the adaptation values to speed up the process. Depending on the current wear condition of your transmission, this can lead to unwanted and permanent bad results.
Will my car still be able to be updated at the dealership?
Yes, you can even leave xHP on your car when you visit your dealer. A dealer software update will simply overwrite the xHP, so you will need to flash it again afterwards.
Will xHP void my OEM or dealer warranty?
xHP changes the calibration file on your TCU. Like any other tuning on your vehicle, this will most likely void your OEM or dealer warranty, depending on your country and/or warranty contract. However, dealer testers will not be able to detect xHP. You don't need to remove xHP before visiting a dealer.