QUOTE(Dougal Cawley @ Apr 18 2019, 10:02 AM)
Sorry, but that is where you are wrong. Your car will handle better on a period 165HR15 or at a stretch a period 185/70VR15 than it will on a 195/65R15. That is just a fact.
Yep a wider more modern tyre will give you greater grip in a straight line than a 165R15. but in the corners it won't unless you modify the car to suit. these cars aren't set up for modern low profile square shouldered tyres unless you lower them, add adverse camber and stiffen the springs etc.
but then you aren't making them handle better quite the opposite, but you are arguably giving them greater road holding which is different. but they won't be anywhere near as nice to drive.
^ Sorry, but that's disinformation.
I've tried my 914 on so many different tires over the last 30 years that I probably couldn't list them if I tried. I've also been evaluating cars as part of my work for 25~ years on both road and track.
The idea that a 914 will handle "better" on 165R15s or 185/70R15s runs counter to so many examples from trusted sources—from Ginther and Johnson in 1970 forward through decades of autocrossers and other 914 tinkerers—that the assertions above are frankly preposterous. You can say a 914 on period 165s or 1985s will handle more "correct" or more "period correct" or "as intended" (and I'd agree), but
better? I'm not so sure there, and I think an argument can easily be made that the 914 chassis was well ahead of the tire technology of its time. In other words, it was ready to employ better tires than were available at the time—and uses them even better with some very minor tweaks (dampers that most cars have since been upgraded to, lower ride height that many 914s now sit at, alignment tweaks, etc—which you do mention).
The best my 914 ever handled was probably on 205/60R15 A-008R TU tires with stiff sidewalls, rounded shoulders, and beautifully predictable breakaway. Downside was too little tire life from the R-compounds of that era—would have loved to try AVS intermediates on a 914, as they were brilliant on other cars I had, including a 911 SC. Next best was probably a 205/55R15 street tire from BFG (Comp T/A 3, iirc), which had a very rounded shoulder. One thing we will agree on is the "square shoulder" of some modern performance tires, and a set of Yoko AVS ES100s with super square shoulders weren't for me, and probably played a part in my desire for something more "age appropriate." So I switched to Vred Sprint Classic 185/70s and loved the ride and delicate steering response—but that was about it. I found the car (a lot) less fun, and ended up giving the Vreds away after 1000~ miles. I'm on Avon CR6ZZ now, and they're okay (wish I had gone softest compound rather than hardest since I'll time them out rather than wear them out), but for me the apex of period "right" and performance came in the 1980s and 1990s with 195/65R15 and 205/60R15 tires such as Yokohama's A-008 and AVSi. Next best was probably Falken's Azenis tires in similar sizing, and then some of the 205/55s.
Have been tempted to try BFG Comp T/As in 205/60R15, but can't quite get over the perception (wrong or right) that they're muscle car tires.
Tires for the 914 are either super easy or very tricky. For some, period tires like the CN36 or XZX/XWX are the only way to fly. I respect that. For others, and all-season is just fine. I respect that, too. For still others, max (or modern) performance from a 205/50, 205/55, or something like that is the way to go. I get that, too. Then there's the rest of us, who are still looking for that Goldilocks 914 tire. I've been looking for it since the demise of the A-008…