The 1.8T engine can come with four different power/torque outputs:

 

Sorry....

1.8T comes with four different power/torque outputs:

150bhp
180bhp
210bhp
225bhp

Now from what I gather they are the same engine, with just different maps. The internals are the same for the 150bhp and 180bhp, I've been told, and that the 210bhp & 225bhp for the S3 simply has a larger turbo. I am considering gettting my A3 remapped, and am just worried about potentially blowing it up.

But if it is the same engine with just a different map, then its no problem... I've seen on a few sites that remaped power for 150bhp & 180bhp goes to 198bhp, so that would make sense. It would also make sense for Audi to have the same engine for all power specs, so that manufacturing overheads etc. are reduced.

 

I have not even heard of a 210hp 1.8T motor.

But the 225hp motor has a K04-20 turbo, which is different from most of the K04-01's that other 1.8T folks upgrade to. The 225hp motor also has forged pistons (and forged something else, I forgot; I was at ECodeTuning and the customer before me had a 225hp TT that was being tuned). That's why the potential of these two motors are different. See e.g. APR's web page on TT ECU reflashes.

http://www.goapr.com/Audi/products/ecu_upgrade_tt.html

 

I imagine it will be forged con rods or a forged crankshaft.

I'm from the UK and was in the US a few weeks ago and was suprised at the fuel you guys run. In the UK standard fuel is 95 octane, and you can now get 99 octane. Your lowest grade is a 89! We do complain over here that the Americans run such large engines with little relative power to our engines, but the lower octane ratings of your fuels would account for some of that, aswell as the need for more torque due to the heavier vehicles.

As regards the 210bhp, it was on the earlier model S3's which I imagine were only released in Europe. It was probably when Audi introduced the 225bhp that the S3 made it across the pond.

 

Yes we do have crappy gas, and the lowest here in California is 87, and the highest is only 91. (Except for a handful of 76 gas stations which offer 100 "race" gas.) In Vancouver, Canada I used to use 94, which was important for highly tuned N/A Honda motors. As for the huge engines with low specific power, it is because the industry was dominated by Detroit products, the latest innovation of which was to rename "pushrods" as "cam-in-block". Hah! Unfortunately, even with the recent increase in gas prices, the U.S. still has the lowest gas prices in the first world, so baby boomers are able to indulge in their teenage infatuation with the V-8 technology from days gone by.

And the S3 never made it over here, the 225hp 1.8T motor is only in our TT.