I had a fully loaded APR Stage 2 ECU tune installed last December and after a few months driving it, I feel it’s time to do a formal write-up and review. Overall, I’m very happy with the modifications, as it definitely made the car more responsive, peppy, and more enjoyable to drive in high-performance driving situations, yet very mild mannered & fuel efficient during normal driving and commutes. The car now feels like a “sports sedan” that drives like it should, as opposed to more of the economy car feel to it from the factory. Here is what my APR Stage 2 setup consists of:
- APR Stage 2 ECU with stock, 91, 93, and 100 performance tunes
- Carbonio Air Intake
- APR Test Pipe
- Billy Boat Quad Tip Exhaust
Driving in the 91 Octane performance tune definitely delivers the power earlier in the power band and more consistently throughout acceleration. Unfortunately, my car has Fronttrak (FWD) and the CVT (Continuously Variable Transmission) so the transmission isn’t the best for the added power because the CVT shifts in pre-set ratios and won’t stay at (or even go all the way up to) redline, so you can only stay at peak power for a brief moment before the transmission automatically shifts for you. It’s also difficult to dyno the power output with this transmission, because you can’t keep the car at redline long enough to get a full power reading without the transmission shifting as well. So my dyno graph shows 225 hp, but probably would have shown another 10+ hp had the transmission let us go all the way up to redline and hold it there a few more seconds. Stock is 200 hp, so although 225 only seems like a +25 hp increase, it’s probably closer to a 35 hp increase. This was performed on a MAHA dyno, which returns more conservative numbers than the more common Mustang dyno, so I’d be interested to see what numbers it could put out on a different dyno. APR’s estimates claim 232hp / 273lb-ft for Stage 1 on 91 octane, but their estimates are difficult to interpret since they use a unconventional dyno that doesn’t measure wheel horsepower directly.
Here is the chart: Nick’s A4 Dyno Chart
The one unfortunate side-effect of going APR Stage 2 is that it made me really wish I had Quattro, as that would have given me the better non-CVT transmission to get more power out of it, as well as added traction to handle the power – my front tires will spin a bit accelerating from a stop at full throttle. But overall I’m very happy with it as the car now performs to its full potential and is a lot more enjoyable to drive. I wouldn’t call it a “beast” but it’s certainly a much needed and very noticeable improvement. I’m also happy that reliability isn’t really affected, especially since I chose to use all APR parts that are designed to work with each other, and APR’s products have been tried and tested by thousands of A4 owners, all with nothing but good things to say.
The car does seem to be at it’s limit, performance wise. I don’t really want to add any more power for fear of causing increased wear on the CVT transmission, and I don’t think the CVT transmission will really deliver that added power to the wheels anyway. If there is one downside to Stage 2, it makes me really wish I had bought a different transmission.