Evening chaps, decided to get a new filter this week, as I found out my CAI currently fited was purchased second hand, so I had no idea how old it was. after reading other peoples experiences, I called up Bill on Monday morning, and placed an order for a JR Jetex cone filter with an 80mm neck to suit an S3 MAF. The filter arrived a few days later. I went for the 80mm neck filter despite having an A3 with 70mm MAF to future proof myself incase I go hybrid at a later date. With this in mind, I used a 70-80mm reducer to join the 80mm filter to my 70mm MAF. So, the old setup: Ebay Cold air induction kit, £40. unknown age. I did some logs on this setup on Sunday night. 6.5 degrees outside temp, V power fuel. I recorded a peak MAF reading of 171.44 g/s. I've done LOADS of logs on the car before, and never gotten more than 171 g/s at all regardless of conditions. So, the filter arrived at work, and I chucked it on in my lunch break: I did a few logs on the way home that evening, sadly I only had Sainsburys 97 RON fuel in her, and the outside temp was 19 degrees. Only did two logs, and recorded a peak of 175.88 g/s. Result! An instant gain of 4.44 g/s, or roughly 5.5bhp. happy days I noticed yesterday that the filter was flopping around a fair bit where I had it, so I looked at ways of making it more secure. The TIP felt more naturally happy if I pushed the filter towards the engine a tad, so what I did, was Pull the filter outwards slightly on the sleeved reducer it's mounted on. This way, the end of the filter sits firmly against the inner wing, and it's all under slight tension, so nothing moves around at all. Very sutble difference, but it makes it much more firm. Did some more logs this morning at 6am, 11 degrees outside temp, and now half way through a tank of V power. First 3 logs showed an average of 179.75 g/s! an increase of 8.31 g/s, or 10.4bhp compared to the old filter, then, after cruising along the A3 at 80mph for 5 miles, I did one final pull, 3rd gear from 3k - redline, and it peaked at 183.75 g/s! A whole 12.31 g/s higher than anything I've ever seen before on the old filter. massively happy! I'm not saying the whole maf / 0.8 thing is 100% accurate, but if the figures are to believed, I started out with around 214bhp, and ended up with 229, a gain of roughly 15bhp. I understand the numbers may be slightly high, but the gains are very real On the road the car feels move lively, and it definitely much more free higher up in the rev range. Perhaps my old filter was really clogged up? who knows. Sorry for the mega long post. I'm not suggesting everyone will gain 12 g/s from fitting a jetex filter, but I just thought it was worth writing up my findings. I'm really happy with the results, and so far I've not noticed any of the heatsoak issues people seem afraid of. For the money, I'm over the moon. I've not had a chance to compare this to a smoothed airbox yet, perhaps I'll throw that in one day and see how it flows. but for now at least, I love the noise this makes!