Erik N
Adventurer
My review of Toyo M-55 255/85/16's
Well, I finally bit the bullet and bought a set of Toyo M-55’s from a Les Schwab dealer. My prerequisite for a new set of shoes for the truck was an E rated tire (for durability) in the 255/85/16 size. That left few options. They replaced a very old set of Chaparral AT’s (made by Cooper, D-rated, narrow with buttery soft sidewalls), which one was kept as a spare. I love to discuss tires, so after about only 900 miles on them on an ’88 Suburban ¾ ton 4x4, here is my review.
The first impression of the M-55 is of their clean, businesslike appearance. As I have posted before, I was seriously considering the Toyo MT as well, but that is such an ugly tire IMO with its tribal tattoo patterns that I just couldn’t bring myself to get them. The M-55’s smooth sidewalls and commercial-looking tread really “match” the classic old-school look of my square-body 'Burb. I like that
...Time (and some mud) will tell if I regret not having an aggressive MT, but as far as appearance goes I am happy.
Next I started fiddling with inflation pressures. I had the tires inflated to 40psi all around at installation, and drove them like that for about 200 miles to break them in. The daytime temps were in the 90’s, so they got in a few decent heat cycles to loosen them up. Others have posted about the M-55’s stiff sidewalls and consequently harsh ride, especially on smaller vehicles. My Submarine weighs 5920lbs unloaded with a full tank of gas. I loaded up the truck with my 2 sons and camping gear and set out for a week of fishing the mountains.
Even loaded w/ roughly 850# of people and gear, plus 40 gallons of gas, 40psi was still (barely) too harsh on pavement. I tried experimenting with the pressures to run them just below the stiff sidewall “slap” over potholes and expansion strips, while monitoring a full contact patch (ie chalk test). The “sweet spot” turned out to be 36psi front/38psi rear, loaded. I would drop a pound or 2 out of that when unloaded. At the proper pressures, they had a comfortable, resilient, confidence-inspiring feel, with almost zero road harshness. I tried running 34psi, but the tall sidewalls would begin to “lean” slightly around higher-G turns when loaded. I would bet that 90% of the population wouldn’t even notice the difference, but I tried to pay attention. The tall sidewall adds to the comfort of the tire, but I could imagine that this tire in smaller aspect ratios (hence shorter sidewalls) could be a harsh ride on lighter vehicles.
On the subject of tall sidewalls, there was a difference of 5psi going from cool AM temps to late afternoon, full sun, hot rolling temperatures. I think the UV rays hitting the huge black sidewall area might account for this large difference in inflation pressure, because my low-aspect ratio Porsche tires only change a few psi at most during the day, unless being beat-up at the track. Also, the pressures increased an additional 1psi for every 1000’ altitude change. As I mentioned before, the “sweet spot” was a sensitive range of pressures, so going from a morning sea-level start up over an 8000’ pass would result in a somewhat “slappy” ride over the torn-up alpine pavement, unless some air was let out along the way.
The sound of the tire is as how others have mentioned. It lets you know there is some traction there, but it’s not obnoxious. It is like an “rrrrrrr” winding-up sound, as opposed to an “AARRRR” sound, or a "HUHRRR" or the “RROWWL” of a mudder. The noise starts quickly on rotation, gets loudest at medium speeds, and dies out around 65mph to wind and engine noise. Incidentally, 65mph is when it tosses out its final bits of gravel from the voids (and it does like to pick up ½” gravel). I thought the noise was actually kind of pleasant to listen to, not an overbearing or demanding sound at all.
The off road driving I did consisted of about 60 miles of dry, rough, rocky trails. IMO, this type of driving is generally where the 255/85/16 size really shines! Their larger diameter helps them roll through rough material more smoothly, and their narrow footprint allows driving around obstacles, rather than over them, allowing more precise tire placement and less bouncing around.
I aired down to about 22F/24R, probably I could have gone way lower but I didn’t feel the need, the tires were supple enough for me there. The sidewalls (gotta love thick sidewalls) at that pressure had a very uniform curvature to them, not “squashed out” like my old tires used to. The pic below is one side of a "V" shaped gully, only the 4 corners of the tires plus some sidewall was holding the truck up.
The terrain was not particularly difficult; probably any reasonable tire would have been fine with 4WD. So it was not a “traction test” at all. I did make a few trips around my dad’s ranch pulling equipment for him up and down very steep, off-camber, dry grassy slopes, that his midsize 4x4 tractor with its “big lug” farm tires wouldn’t grab on safely (the first trip was actually pulling up the tractor, which was pulling a water tank with a few hundred gallons in it). The M-55’s slid around quite a bit, but I think anything would in those conditions anyway. I will say that they did not suffer a single sidewall cut or a single torn lug or shoulder chunk… they are hardly even scuffed. They have a reputation for being a trustworthy, indestructible design, and so far that appears to be true!
That’s it for now. I will be heading out again in mid-October; maybe I will get some snow or mud to comment on then. Adios :sombrero::beer:
Well, I finally bit the bullet and bought a set of Toyo M-55’s from a Les Schwab dealer. My prerequisite for a new set of shoes for the truck was an E rated tire (for durability) in the 255/85/16 size. That left few options. They replaced a very old set of Chaparral AT’s (made by Cooper, D-rated, narrow with buttery soft sidewalls), which one was kept as a spare. I love to discuss tires, so after about only 900 miles on them on an ’88 Suburban ¾ ton 4x4, here is my review.
The first impression of the M-55 is of their clean, businesslike appearance. As I have posted before, I was seriously considering the Toyo MT as well, but that is such an ugly tire IMO with its tribal tattoo patterns that I just couldn’t bring myself to get them. The M-55’s smooth sidewalls and commercial-looking tread really “match” the classic old-school look of my square-body 'Burb. I like that
...Time (and some mud) will tell if I regret not having an aggressive MT, but as far as appearance goes I am happy.Next I started fiddling with inflation pressures. I had the tires inflated to 40psi all around at installation, and drove them like that for about 200 miles to break them in. The daytime temps were in the 90’s, so they got in a few decent heat cycles to loosen them up. Others have posted about the M-55’s stiff sidewalls and consequently harsh ride, especially on smaller vehicles. My Submarine weighs 5920lbs unloaded with a full tank of gas. I loaded up the truck with my 2 sons and camping gear and set out for a week of fishing the mountains.
Even loaded w/ roughly 850# of people and gear, plus 40 gallons of gas, 40psi was still (barely) too harsh on pavement. I tried experimenting with the pressures to run them just below the stiff sidewall “slap” over potholes and expansion strips, while monitoring a full contact patch (ie chalk test). The “sweet spot” turned out to be 36psi front/38psi rear, loaded. I would drop a pound or 2 out of that when unloaded. At the proper pressures, they had a comfortable, resilient, confidence-inspiring feel, with almost zero road harshness. I tried running 34psi, but the tall sidewalls would begin to “lean” slightly around higher-G turns when loaded. I would bet that 90% of the population wouldn’t even notice the difference, but I tried to pay attention. The tall sidewall adds to the comfort of the tire, but I could imagine that this tire in smaller aspect ratios (hence shorter sidewalls) could be a harsh ride on lighter vehicles.
On the subject of tall sidewalls, there was a difference of 5psi going from cool AM temps to late afternoon, full sun, hot rolling temperatures. I think the UV rays hitting the huge black sidewall area might account for this large difference in inflation pressure, because my low-aspect ratio Porsche tires only change a few psi at most during the day, unless being beat-up at the track. Also, the pressures increased an additional 1psi for every 1000’ altitude change. As I mentioned before, the “sweet spot” was a sensitive range of pressures, so going from a morning sea-level start up over an 8000’ pass would result in a somewhat “slappy” ride over the torn-up alpine pavement, unless some air was let out along the way.
The sound of the tire is as how others have mentioned. It lets you know there is some traction there, but it’s not obnoxious. It is like an “rrrrrrr” winding-up sound, as opposed to an “AARRRR” sound, or a "HUHRRR" or the “RROWWL” of a mudder. The noise starts quickly on rotation, gets loudest at medium speeds, and dies out around 65mph to wind and engine noise. Incidentally, 65mph is when it tosses out its final bits of gravel from the voids (and it does like to pick up ½” gravel). I thought the noise was actually kind of pleasant to listen to, not an overbearing or demanding sound at all.
The off road driving I did consisted of about 60 miles of dry, rough, rocky trails. IMO, this type of driving is generally where the 255/85/16 size really shines! Their larger diameter helps them roll through rough material more smoothly, and their narrow footprint allows driving around obstacles, rather than over them, allowing more precise tire placement and less bouncing around.
I aired down to about 22F/24R, probably I could have gone way lower but I didn’t feel the need, the tires were supple enough for me there. The sidewalls (gotta love thick sidewalls
) at that pressure had a very uniform curvature to them, not “squashed out” like my old tires used to. The pic below is one side of a "V" shaped gully, only the 4 corners of the tires plus some sidewall was holding the truck up.The terrain was not particularly difficult; probably any reasonable tire would have been fine with 4WD. So it was not a “traction test” at all. I did make a few trips around my dad’s ranch pulling equipment for him up and down very steep, off-camber, dry grassy slopes, that his midsize 4x4 tractor with its “big lug” farm tires wouldn’t grab on safely (the first trip was actually pulling up the tractor, which was pulling a water tank with a few hundred gallons in it). The M-55’s slid around quite a bit, but I think anything would in those conditions anyway. I will say that they did not suffer a single sidewall cut or a single torn lug or shoulder chunk… they are hardly even scuffed. They have a reputation for being a trustworthy, indestructible design, and so far that appears to be true!
That’s it for now. I will be heading out again in mid-October; maybe I will get some snow or mud to comment on then. Adios :sombrero::beer:
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