Hi, what is the source for this? i'm interested in seeing the data for the 20 inch tires. thanks!
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Just checking in on how you are liking this tire size on your Gemini wheels. How is your efficiency now? Any fitment issues going up a tire size? How much more ground clearance did you get. Thanks in advance for any additional info.
I'm very happy with the tires. The tire is 1" taller, so there is 1/2" more ground clearance.
No fitment issues, but you cannot go any larger.
Overall efficiency is down 7%.
Dry traction and steering response aren't as good, but not bad. Rain performance is much better, and snow performance is much much better. They are quieter, less prone to induce the boominess, and much smoother.
I just replaced my Model Y LR / 19" original Continentals with a set of four General Altimax RT45 tires. With my specific driving pattern, I'm not seeing any significant range decrease or apparent efficiency loss compared to what I was used to. I've got over 1000 miles on the new tires so far. Not any noticeable noise level difference on smooth pavement for me either, and on rough/cracked pavement the Generals (no foam) might be a bit noiser than the Continentals (with foam).
Longer version, with details:
Got my car in December of 2021. A couple months ago, at right around 29,000 miles with regular rotations, the original Continentals on my 7-seat Model Y LR still weren't down to the wear bars and had a bit of life left...but then I got a non-repairable screw near the edge of one of the tires.
So, I replaced all four with the General Altimax RT45's as they looked pretty decent to me, and the price was (IIRC) $100+ lower per tire.
At least on my specific commute* any efficiency difference must be in the single digits and within the noise of what I would notice. The consumption per trip is always within the range I expect, within the normal bounds I see due to varying wind and if I needed to drive a bit faster or slower that day. I wll admit that I probably over-inflate my tires by a few psi, but I did that with the Continentals too. I live in the mountains...so over-pressure a bit partially for efficiency, but also so if I get a morning that's suddenly 20 degrees colder, I don't see the tire pressures lower than the target 42 psi. The car is reading my tires at about 43-44 psi when I start off, although my cheap slideys/stick pressure gauge I use reads them at about 46-47 psi.
The new tires also don't have the sound-dampening foam that the Continentals did, but I don't notice much difference there. On smooth pavement, the new tires are silent as far as I can tell. On rough-ish pavement (where the asphalt is more grey and the surface gravel is showing a bit), there is a little more noise than I remember the Continentals having, but it's stll quiet. The General Altimax RT45's do seem a bit noisier when I'm driving over sections of road that have lots of cracks that look like there will soon be lots of potholes...but that doesn't bother me and I blame the road. It's also a good warning to watch ahead to see if there are any potholes that need avoiding
.
*As for my specific commute and driving: I keep up with traffic, but am not generally an agressive driver. Most of my accelerations and decelerations are gentle. I live in the Southern California mountains, at about 6100 feet, and work out in the desert. My commute drops to a low elevation of about 2000 or 2500 feet, and my work site is on a hill at about 3000 feet elevation. The drive is about 63 miles each way, mostly 55-65mph driving on 2-lane highway roads (1 lane each way). There are a few stop signs and a few traffic signals along the way, but much of it is cruise control/FSD driving at those moderate highway speeds. My commuting time is just me in the car...but I also take many drives with the family...up to and including Wife + 4 kiddos (ranging from 40-100 lbs) + dog (65 lbs). After getting the new tires, we did a recent family trip to an amusement park (all the humans, but no dog). That was a ~180 mile round trip, with some driving in traffic, and also some ~80mph driving. I think I charged up to 250-255 miles that morning, lost some miles during the day due to Sentry Mode, and got back home with about 50 miles to spare. That was in line with what I'm used to, and seems pretty good to me especially considering the faster driving and ~5000+ feet of elevation increase with 6 people in the car to get home (you lose more on the way up than you gain from regen on the way down ).
Longer version, with details:
Got my car in December of 2021. A couple months ago, at right around 29,000 miles with regular rotations, the original Continentals on my 7-seat Model Y LR still weren't down to the wear bars and had a bit of life left...but then I got a non-repairable screw near the edge of one of the tires.
So, I replaced all four with the General Altimax RT45's as they looked pretty decent to me, and the price was (IIRC) $100+ lower per tire.
At least on my specific commute* any efficiency difference must be in the single digits and within the noise of what I would notice. The consumption per trip is always within the range I expect, within the normal bounds I see due to varying wind and if I needed to drive a bit faster or slower that day. I wll admit that I probably over-inflate my tires by a few psi, but I did that with the Continentals too. I live in the mountains...so over-pressure a bit partially for efficiency, but also so if I get a morning that's suddenly 20 degrees colder, I don't see the tire pressures lower than the target 42 psi. The car is reading my tires at about 43-44 psi when I start off, although my cheap slideys/stick pressure gauge I use reads them at about 46-47 psi.
The new tires also don't have the sound-dampening foam that the Continentals did, but I don't notice much difference there. On smooth pavement, the new tires are silent as far as I can tell. On rough-ish pavement (where the asphalt is more grey and the surface gravel is showing a bit), there is a little more noise than I remember the Continentals having, but it's stll quiet. The General Altimax RT45's do seem a bit noisier when I'm driving over sections of road that have lots of cracks that look like there will soon be lots of potholes...but that doesn't bother me and I blame the road. It's also a good warning to watch ahead to see if there are any potholes that need avoiding
.*As for my specific commute and driving: I keep up with traffic, but am not generally an agressive driver. Most of my accelerations and decelerations are gentle. I live in the Southern California mountains, at about 6100 feet, and work out in the desert. My commute drops to a low elevation of about 2000 or 2500 feet, and my work site is on a hill at about 3000 feet elevation. The drive is about 63 miles each way, mostly 55-65mph driving on 2-lane highway roads (1 lane each way). There are a few stop signs and a few traffic signals along the way, but much of it is cruise control/FSD driving at those moderate highway speeds. My commuting time is just me in the car...but I also take many drives with the family...up to and including Wife + 4 kiddos (ranging from 40-100 lbs) + dog (65 lbs). After getting the new tires, we did a recent family trip to an amusement park (all the humans, but no dog). That was a ~180 mile round trip, with some driving in traffic, and also some ~80mph driving. I think I charged up to 250-255 miles that morning, lost some miles during the day due to Sentry Mode, and got back home with about 50 miles to spare. That was in line with what I'm used to, and seems pretty good to me especially considering the faster driving and ~5000+ feet of elevation increase with 6 people in the car to get home (you lose more on the way up than you gain from regen on the way down
).
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In case anybody is interested, USAA offers a whopping 30% off of Goodyear tires through their website. . . .
Would like to get a general opinion about acoustic foam. Yay or nay? I remember an a long time a go that said tests showed it didn't do much. I went from the MXM4s with foam on my old M3 to Continental Extreme Track with no foam and never really noticed a diff.
I'd be more interested in a self-sealing tire but the brands that have it don't seem to sell them in the US except for commercial trucks.
Would like to get a general opinion about acoustic foam. Yay or nay? I remember an a long time a go that said tests showed it didn't do much. I went from the MXM4s with foam on my old M3 to Continental Extreme Track with no foam and never really noticed a diff.
I'd be more interested in a self-sealing tire but the brands that have it don't seem to sell them in the US except for commercial trucks.
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