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      09-27-2020, 12:24 PM   #1
alehax
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Back tyres 265/30/R20

hi guys

I am looking to replace my tyres and found some 265/30 R20 instead of 275/30 R20. Will this affect the drive? I am thinking with the winter coming maybe going down on the width would marginally help. What's your take on this?
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      09-27-2020, 04:34 PM   #2
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Quote:
Originally Posted by alehax View Post
hi guys

I am looking to replace my tyres and found some 265/30 R20 instead of 275/30 R20. Will this affect the drive? I am thinking with the winter coming maybe going down on the width would marginally help. What's your take on this?
Could very well cause you issues if your an x-drive. The system is designed so the front and rear diameters are within 1% of each other.
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      09-28-2020, 08:04 AM   #3
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And still if you choose fitting pairs ( foreaxmple I did choose 225/45/19 and 255/40/19) which are ok regarding charts they might be something else ..... you're only safe with e-drive if you have same tire in every corner.

That mentined pair should be with 1 cm. circle but are not while the front tire has round 6 mm. less distance to ground when standing still.
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      09-28-2020, 10:57 AM   #4
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Quote:
Originally Posted by alehax View Post
hi guys

I am looking to replace my tyres and found some 265/30 R20 instead of 275/30 R20. Will this affect the drive? I am thinking with the winter coming maybe going down on the width would marginally help. What's your take on this?
Are you considering mounting the 265/30/20 on all 4 wheels or just the rear wheels?

The goal (for not creating issues) is to maintain the rolling circumference/diameter on both axles within spec as previously mentioned. You can easily google for a wheel/tire calculator and run your existing wheel/tire sizes and offsets against a new setup to see how close or far off you are.

Using this site: https://www.1010tires.com/Tools/Tire-Size-Calculator .. it appears that the 265/30/20 is -.89% different...which means it is within the (+/-) 1% range (see pic below). But again, it is NOT clear if you are running this tire on all 4 corners or only in the rear. If its the latter and you're only looking at the rear, then you need to compare the front to rear to see if they have rolling diameter/circumferences that are greater than 1%.
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      09-28-2020, 03:54 PM   #5
alehax
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thank you guys, very helpful (as usual). My plan is to have 265/30 R20 on the rear axle only (a friend of mine has a pair of brand new Conti Sport Contact 5 and willing to part with them for £200 both). The idea is that the front would remain the same (245/35 R20), obviously as you guys said there is a difference in diameter and don't want to do it if it does creates problems (even at the bargain price for them). As I see it and as you mentioned it the difference is under 1% so not sure what to do, if too much of a headache I will give it a miss..
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      09-28-2020, 04:55 PM   #6
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Quote:
Originally Posted by alehax View Post
thank you guys, very helpful (as usual). My plan is to have 265/30 R20 on the rear axle only (a friend of mine has a pair of brand new Conti Sport Contact 5 and willing to part with them for £200 both). The idea is that the front would remain the same (245/35 R20), obviously as you guys said there is a difference in diameter and don't want to do it if it does creates problems (even at the bargain price for them). As I see it and as you mentioned it the difference is under 1% so not sure what to do, if too much of a headache I will give it a miss..
Correct. I would not suggest or recommend that setup. Diameters are too different (almost 2%), especially since the rear will wear faster and create even a greater difference.
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      09-30-2020, 04:35 PM   #7
alehax
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Quote:
Originally Posted by AccordTR View Post
Correct. I would not suggest or recommend that setup. Diameters are too different (almost 2%), especially since the rear will wear faster and create even a greater difference.
That's a very valid point mate, thank you. I will stick to OEM size, I am sure they spent millions to find the correct wheel diameter for the car. Them Germans will yell at me " but wat are you doing man, zis is not korrect size for zha car, are you crezy" no offence to my fellow Germans, I love them!
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