Yes. Prices vary, some companies charge around £600 or so for the recoding.
The TDI 90, as you've probably seen, doesn't have an intercooler. The TDI
110 (and 115, 130, 150, so on and so forth) are intercooler, and also have other funkiness. But they're essentially the same donk. As a disclaimer, this is a huge simplification, however it'll do for here! :pWell..... I guess it'll depend on how hard you drive it. If you're caning it then it's possible that you'll break something, however you'll be breaking something sooner that was already going to break.
As I recall, the transmission wasn't materially or substantially changed for the mark four Golf, nor between TDI 90 and 110 models... but don't quote me on that.
I've chipped and tweaked many cars. What I've found is that in the city, it makes no difference, not that one would expect one, heh! On the motorway, the difference depends on the car and the driver. When driving gently over a hilly route, it can make quite a difference.
The most recent example is Kermit. His recoded ECU has flattened the torque curve, so now he's producing >100% of original maximum torque output from
2,000 to 4,500 rpm :) which makes him noticeably more tractable. If During my commute and being gentle, fuel consumption is down from 45 mpg to ~47 mpg.Not to mention the 0.8 second improvement in quarter mile times, too! :p