The 325/40 R21 size is one of the extremely wide high-performance tire sizes , which is mainly used on large luxury SUVs , powerful performance SUVs , AMG/M/RS models and electric high-performance vehicles .
With a massive 325 mm tread and a stable 40 mm cross-section, this dimension offers:
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maximum traction
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exceptional lateral stability
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short braking distances despite vehicle mass
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High directional stability at motorway speeds
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optimal power transmission at high torque
Vehicles that use 325/40 R21 tires almost always have:
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very high axle loads
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large brake systems
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Sport or air suspension systems
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All-wheel drive systems (xDrive, Quattro, 4Matic)
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electric high-performance drives with instant torque
Used tires in this category require more intensive inspection, as even small structural defects can be safety-critical under these loads.
✔ Vehicle types that commonly use 325/40 R21
Large performance SUVs
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BMW X7 (M Sport / M50i)
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Mercedes GLS (AMG Line, GLS 580, GLS 63)
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Audi SQ7 / SQ8 (models with wide rear axle design)
Luxury SUVs & Top-of-the-range models
Electric SUVs & EV Performance Vehicles
All-wheel drive vehicles (AWD/4x4)
🔧 Technical test criteria for used 325/40 R21 summer tires
1. Tread depth & wear analysis
The following will be checked:
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sufficient remaining tread depth
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Even wear despite high vehicle loads
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no block cracks or signs of overheating
2. DOT analysis & material evaluation
Important due to thermal stresses:
3. Carcass & Structure Inspection
This dimension is absolutely crucial:
4. Runout & Vibration Test
Relevant for:
5. Load Capacity & Speed Index (LI/SI)
Especially important for:
6. Air tightness test
Each tire is checked for constant pressure loss.
🛠 Tyre44 testing procedure for used 325/40 R21 summer tires
All tires are checked for:
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digital tread depth measurement
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DOT analysis & material evaluation
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Carcass and structural integrity
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Runout and vibration measurement
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Airtightness
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OEM-compliant rolling circumference values
→ Only tires in absolutely perfect technical condition are included in the Tyre44 product range.
🧊 Summer tire offer in 325/40 R21 (used) at Tyre44
We offer:
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tested used high-load summer tires
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DOT and tread depth variants as required
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XL/reinforced models for extreme load capacity
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Performance-optimized summer profiles
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affordable alternatives to new tires
🔍 Easily select suitable used summer tires
With the Tyre44 vehicle filter
(Manufacturer → Model series → Model name)
You will receive tires that:
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fully compatible with 325/40 R21
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Load capacity and speed indices are met
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Adhere exactly to OEM rolling circumference
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Ideally suited for large SUVs, luxury models, EVs & AWD vehicles
→ No more bad purchases.
⭐ Why Tyre44?
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Strictly inspected used summer tires in size 325/40 R21
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documented DOT and tread depth information
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fast delivery throughout Europe
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Premium quality at an attractive price
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Maximum stability, safety & performance
Order your tested used summer tires in size 325/40 R21 now – extremely durable, wide & performance-oriented! 🚀