The Audi bolt-down ones are good. I replaced the push-down coils that had a failure about every year or two with the bolt-downs just a week or so befor VW announced the recall. Zero, zero, zero problems ever since.
So far I've replaced all ignition coils (1 died while I was test driving the car, the other 2 years after in the winter, of course). I decided to replace them all with non-faulty Audi parts instead of doing it every year.
Coils I've tested as follows:MSD, Blaster ss/Accel electronic super coil/Accel canister OE replacement/Audi 5KTurbo OE \"E\" core epoxy coil/Ford OE EEC-IV(TFI) E core coil. Results..OEM VW canister oil coil=unable to increase plug gap/difficult starting *sometimes, rough idle MSD Blaster coil=seemingly quicker starts, smoother idle, able to increase plug gap, coil runs hot Accel electronic(square super coil)=pure junk, worked as well as the MSD for starting, however upper revs missed with gap opened, and coil failed within 1 year Accel canister coil(OE replacement)=no noticeable difference from VW OEM coil Ford TFI/EEC-IV \"E\" core coil=plug gap opened larger than MSD, no missing, coil runs at normal temp, quick starts, smooth idle(best of tests of all coils)however;these are known to fry occasionally, must keep a spare. Audi 5KTurbo OE \"E\"core coil=plug gap limited to 0.034\" from 0.028\", easily handles up to redline without missing, runs cooler than other coils, good starting all weather and smooth idle. I currently use the Audi OEM 5K Turbo \"E\" core epoxy/plastic coil and combined with MSD 9mm(50ohms/per foot) custom made wires and the re-wiring of the coil(+)terminal with a Bosch 40Amp relay with 8gauge(Monster Cable) power wire with gold plated terminals........the reason for re-wiring was I noticed around a 1volt drop between the battery and the coil(+)terminal, after adding relay/power wire(10gauge would be fine as well)the voltage is exactly battery voltage...after re-wiring the coil I was unable to ever get any missing in the higher RPM's. And a slight increase in power*seemed* to be felt, but no dyno proof....gas mileage did increase about 4 miles/gallon!!(original mileage was probably poor from crummy OEM wiring)
I found the 86 gti engine (8V)running the cis-e jetronic would actually work fine with revs up 7K even in hot weather without problems, but the wimpy 0.028\" spark plug gap left me wondering if I could improve my idle/fuel mileage/BHP.....so I opened it up to 0.030\" and ran the same test(using OE coil/wires)...... engine @191F/5800RPM travelling up a 4degree slope and 92octane at sea level with 26Celcius ambient outside temps, and the engine began to \"miss\", swapped coil out for aftermarket unit and no miss was felt until 6400RPM, changed the wires to aftermarket(50ohms/ft, 9mm spiral) and voila!...no miss right up to 7Krpm...........Opened my plug gap to 0.032\", no missing or noticeable problems, opened gap to 0.034\", slight miss beginning at 6700rpm........Swap out ignition coil for another different coil, and rewired battery to engine/body and replaced power wire to ignition coil with a relay and 8gauge power wire from battery......0.034\"..revs to 7Krpm no problems and after rewiring, opening plug gap to 0.034\", car now idles smoother, starts better and is slightly better on fuel......downside so far is distributer cap and rotor wear out faster than usual.............notice I did not mention any \"brands\", however, from my own testing, I believe that the O.E ignition wires are junk, and the wiring to the coil/battery/engine need to be upgraded, the coil is probably satisfactory but I personally hate canister oil type coils(E-core resin ones seem best) Don't think I gained much anything for HP but maybe 1Hp with larger plug gap/cleaner & better HV to plugs.........again, this was all free for me to test and keep, but for probably $150 I would certainly upgrade the wires and coil and basic chassis wiring. But, if you don't like messing with your plug gap and don't plan on reving past 6K or are satisfied with fuel mileage, it's probably not worth doing.......I run an MSD 6AL in my Xr4Ti, but that's a different reason., and no I didn't notice any difference from the OE EEC-IV TFI, I wanted a fancy rev limiter that looked good under the hood. P.S. One of the best working coils I used wasn't aftermarket!....I got my BEST results with an OE Audi 5KTurbo epoxy E core type coil!
