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I have 2014 C250 on a staggered setup and I am about to replace my rear tires. My front tires basically new and the speed rating is 91H. My question is does my rear tires have to be 91H as well or can I have 95W on the back and 91H on the front?
You can have a higher speed rating in the rear than required given the top speed of the vehicle. You just need to make sure the speed rating of the tires is high enough for the speed you are planning on driving. Since you are located in the USA, even H is way more than you need. H is up to 130mph and W is up to 168mph.
The load rating is a different story. That's the number before the letter. The load ratings can be different front to back due to the weight distribution and increased load on the rear with RWD vehicles for example. Also depends on tire pressure and size of the wheels. From what I can find it sounds like you have the 17" wheels where the stock tires are 91H front and rear. However, with the 18" wheels the same car uses 92H in the front and 94H in the rear. So higher load ratings overall, perhaps to compensate for the shorter sidewall, but also higher load rating in the rear.
Having said that, the amount of load that the tire can carry doesn't just depend on the load rating, but also the tire pressure. The load rating specifies the max load the tire can carry at the max tire pressure found on the sidewall of the tire. That's typically around 50 psi. At lower tire pressure it can carry less load, so the load is always a combination of load rating and the tire pressure you use. Tires with higher load rating and/or higher pressure are stiffer and therefore ride less comfortable, so by using a tire with a higher load rating as your stock tires and inflating them to the same tire pressure will result in a less comfortable ride. So what you can do is lower the tire pressure, because a higher load rating of the tire means you don't need as high of a tire pressure to have it carry the same load as your lower load rating stock tires.
Last edited by superswiss; Jul 31, 2025 at 05:06 PM.
So you want to replace your worn rear tires and the new tires you want to get have a higher speed rating? Sounds good to me. I'm hardly a tire expert but its something I would do. Seems the higher the speed rating the better handling of the tire. Then next time you replace the fronts look for the W speed rating.
I had all 4 tires replaced last year and they are 95W XL M+S. I really like them. I guess the XL means extra load. I figured in my mind they are good in case of hitting pot holes they may be more durable. I have the staggered 17" rims and the tires look low profile-ish. I drive normal though, im not zipping around drifting around corners.
225/45R17 95W XL M+S front
245/40R17 95W XL M+S rear
This all makes sense. I'm going to get the 95Ws for the rear and keep the tire pressure lower. When I get the new fronts I'll get 95Ws to match the rear. Thanks guys.
Look on the inside of the drivers door at the tire info. I would follow what it says for the tire pressure. Im assuming you will be getting the recommended size tires on that label.
Theres alot of info on tires in the Operators Manual.
Quick story about tire pressures. When I got my tires replaced last year I got in the car and started driving away. Almost immediately the tire pressure warning popped up on the dash. I figured it was due to having two of the old sensors replaced with new ones I bought for them to swap out, along with supplying them with the rebuild kits for the other two sensors I was keeping, the car had to relearn the sensors. As I was driving the ride felt extremely hard feeling every single bump, like the car was bottoming out. I was thinking the tires suck. Then the tire warning went away and it showed the pressure of all 4 tires and they were around 50psi when the front should be 30psi and the rears should be 35psi according to the label on the door. I pulled over in the first parking lot I came across and I lowered all the tires to the correct pressure and the car rode great after that. I went from hating the new tires to loving them just by correcting the pressure. This also showed me the tire shop couldnt be bothered to even look on the door to what the pressure should be. Then when I got home I was cleaning the rims because they were filthy and thats when I noticed they had broken two center caps and glued them back on with some type of clear sealant.
So as long as you are getting the recommended size tires and the tires meet the car load rating I would set the the tire pressure according to what it says in the door.
How are the tire pressure sensors? Since owning my 2010 I have replaced all four sensors. Two had died so I replaced them myself then I replaced the remaining two when I had the tires replaced. Because two sensors were pretty new i just had the tire shop rebuilt them while the tires were off. Living in New England the stems get corroded. I had a Jeep before with similar sensors and the stems broke while filling the tires with air they were so corroded.
Mine has the black MB sensors and I used Schrader rebuild kits. Part# 20013 has the nut, little round piece, cap and valve core. The stem is Part# 20020 ( I think).
This all makes sense. I'm going to get the 95Ws for the rear and keep the tire pressure lower. When I get the new fronts I'll get 95Ws to match the rear. Thanks guys.
If you happen to go outside of Mercedes recommendations (different tire sizes, different pressures, speed ratings above W, or unrated competition tires) just be sure to check tire wear across the tread at 3000 and 6000 miles. If the outer edges are wearing faster, increase pressure by 2 psi. If the center is wearing faster, decrease pressure by 2 psi. This will keep the contact patch flat, maintain maximum traction, and give the longest tire life. The Y+ tires I put on my W204 needed the extra 2psi.
2023 E 450 Sedan. 2018 GLC 300. 2013 E 350 Coupe (retired)
The correct tire pressures for your specific vehicle are listed on a sticker placed on the inner side of the fuel door. The sticker on the door jam are maximum for the tire. Not what to use for your car.
When Z-speed rated tires were first introduced, they were thought to reflect the highest tire speed rating that would ever be required, in excess of 240 km/h or 149 mph. While Z-speed rated tires are capable of speeds in excess of 149 mph, how far above 149 mph was not identified. That ultimately caused the automotive industry to add W- and Y-speed ratings to identify the tires that meet the needs of vehicles that have extremely high top-speed capabilities.
Speed Rating Speed mph Speed km/h Category
W 168 mph 270 km/h Exotic Sports Cars
Y 186 mph 300 km/h Exotic Sports Cars
While a Z-speed rating still often appears in the tire size designation of these tires, such as 225/50ZR16 91W, the Z in the size signifies a maximum speed capability in excess of 149 mph, 240 km/h; the W in the service description indicates the tire's 168 mph, 270 km/h maximum speed.
Tire Size Speed 225/50ZR16 in excess of 149 mph, 240 km/h 205/45ZR17 88W 168 mph, 270 km/h 285/35ZR19 99Y 186 mph, 300 km/h
When the Y-speed rating indicated in a service description is enclosed in parentheses, such as 285/35ZR19 (99Y), the top speed of the tire has been tested in excess of 186 mph, 300 km/h indicated by the service description as shown below:
Tire Size Speed 285/35ZR19 99Y 186 mph, 300 km/h 285/35ZR19 (99Y) in excess of 186 mph, 300 km/h
Last edited by MB2timer; Aug 1, 2025 at 07:10 PM.
Reason: Para
I bought my current tires from Amazon. The tires came out to around $310 w/tax then I bought the installation which was a little under $100. My old tires looked to be wearing fine and the car drives straight so I skipped an alignment.
Had them on for 14 months now and I love them. Quiet and smooth. I would buy them again.
They should have the UTQG rating on them with tread wear. My tires had it on the labels stuck to the tires. They say treadwear is 480. I guess 400 is 40,000 miles and 500 is 50,000 miles.
All tires have treadwear rating, but it doesn't have any standardized meaning. 400 doesn't mean 40k miles etc., and you can't even use it to compare across manufacturers as there is no standards body that measures and certifies the treadwear. So each manufacturer decides what it means for them. 400 means that it lasts 4 times longer than a tire from the same manufacturer with a treadwear of 100. However, what 100 means is up to the manufacturer. 100 could mean 5k miles, it could mean 10k miles, it's whatever their internal baseline is.
Yeah, tread wear even varies between cars. Alignment and such is a big factor, and tread wear warranties are cut in half for staggered setups for example where rotation isn't possible. So a 30k miles warranty gets cut to 15k miles warranty if the tires can't be rotated.
Last edited by superswiss; Aug 2, 2025 at 02:06 AM.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
