@12many I realize you already bought them but you might still appreciate the info below. Your feedback will probably be more helpful than this but nevertheless, here's a writeup from the Impala forum (that I go to...never but it came up in a search). This guy is running 255 and 275 on his Roadmaster wagon, not sure how this affects the relevancy of his feedback. This certainly sounds promising.
I Tried a New Tire (Vitour Galaxy R1)
User: GoremanX
Apr 7, 2021
While shopping for tires for my car, I couldn't find any writeup of these tires on a GM B-body, so I figured I'd put one together to help anyone who considers these in the future.
When I bought my '93 Roadmaster wagon last Fall, the alignment was WAY off. Consequently, the front tires were pretty much finished while the rears were fine. Due to lack of funds at the time, I settled for buying a new pair rather than a full set. So I've been running mildly-worn General Altimax in front, and brand new Crugen HT51's out back, both in 235/70R15 on factory original aluminum 15x7 wheels. They've been decent and comfortable, but nothing to brag about. Especially with the rear swaybar I installed recently, the limits of those tires were more obvious than ever.
For this year, I decided to put on something a little more "spirited", and experiment a bit with size. I wanted to keep the OEM 15" wheels. Based on other posts on this forum, I figured 255 or 275 tires should fit, so that's mostly what I looked at.
I kept coming back to the Cooper Cobra Radial G/T, but like everything else in these sizes for 15" wheels, it's only got a speed rating of T. I don't necessarily plan to drive at 120+mph for extended periods of time, but in my experience, tires with a lower speed rating tend to have super flexy sidewalls. I really wanted something with a speed rating of H or V. I've run Cooper Cobra G/Ts on other cars in the past ('78 Trans Am, '71 Datsun Z), and came away unimpressed. They're very much an "older" style of tire.
Enter the Vitour Galaxy R1. I don't know if Vitour has a common parent company. It looks like they're a South African company, though I'm not even sure about that. They're made in China according to the TIN code on the tire. These tires are available in most of the sizes that the Cooper Cobras are (so, a lot of classic car sizes), except they have a much more modern tread pattern that's intended to be performance-oriented. They also have a speed rating of H or V, which is much higher than the S or H that's prevalent in these sizes. Their price is downright reasonable, too.
My next dilemma was to choose sizes. I disabled ABS on this car, so a staggered setup is a possibility (255/60R15 front, 275/60R15 rear). Or I could stick to the OEM size (235/70R15). Or I could balloon-up all around (255/70R15). I ended up going with the latter option. My logic is that I like the bump-smoothing of taller sidewalls and greater air volume at lower pressure. If it compromised handling too much, well... they have a wear rating of 400, so it's not like they'll last all that long anyways (for comparison, Cooper Cobras have a wear rating of 440) If I want something more aggressive next time, maybe I'll try the staggered setup. Everything's a compromise anyways...
I received the tires a couple months ago from Performance Plus Tire and they've been sitting in my garage ever since. They're gorgeous. The tread pattern looks really modern, the compound is grippy, and the white letters look real nice. I dunno how long they'll stay white, it's just a thin coat of paint on the molded rubber, but I can always re-apply it if it wears off prematurely. I don't get why they say M+S on them... they'd make a real lousy snow or mud tire. I wouldn't run these on anything but pavement and never below 42f.
Nov 5, 2021
Thought I'd give an update after a summer on these tires. I've been driving the crap out of them, giving my swaybars a heavy workout and taking every corner aggressively. These tires are like glue. I absolutely love them. Especially in the rain, they've been remarkably grippy. The temperatures have been dropping into overnight freezing the last couple days, and they take a while to warm up from that, but beyond that these tires have excelled in every conceivable way. The steering is precise, the response is quick (especially considering the height of those sidewalls), the ride is comfortable, and there's no real concern with noise. They've kept their balance through thousands of miles and they hauled almost 1000 pounds in the rear without complaint. Wear has been minimal, they still look new after close to 8000 miles. I couldn't be happier.