[museek]

Hi friends

I have owned an S5 for 2 years now and have driven it for almost 30000 kms. I own a Troc and Polo GT as my other cars. I love to use my cars everyday and everywhere, and that was one reason I got the S5 and not the RS5.

But even in this car, I keep on running into small problems with the tyre and wheel combo. The original R19 has 255/35 tyres. Have had 2 rim replacements and 3 tyres replaced. Once I lost 2 tyres in the same instant...a huge moon crater-sized pothole and my car doing maybe 40kmph.
Now am planning to maybe switch to R18. Tyre options for this are 245/40 and 225/45.

Which is better - 245 or 225?

Will it be worth it just for the peace of mind or will technical issues again sabotage my ride?

[bijims]

I usually like to keep things stock, those tires have been made stock because perhaps they are the best for their use case. However upsizing or downsizing is a personal preference and if you feel it will work for you, why not ?

Given your experience with rim and tire damage, the 225/45 R18 might be a better choice for peace of mind. The increased sidewall height will offer better protection against potholes and rough roads, and the lighter weight can improve overall handling and efficiency.

[AMG Power]

Always buy a car that suits your driving style (if you cannot change it), suitability for roads you use regularly and your usual driving cycle.

40 kmph is a very high speed for a moon crater sized pothole - something that only tough SUV’s can come through unscathed.

Both the tyre options suggested could land you in trouble in other areas as you are reducing the width in a performance car. This could result in problems in other areas - loss of traction during panic braking, reduced high speed grip and reduced handling.

The roads you use regularly coupled with your driving pattern do not appear to make the S5 the right choice of car. As you have other cars, an option is to use the S5 on highways only and use your other cars for your daily driving cycle.

[androdev]

Check the recommended tire pressure sticker on your car. It's either on fuel filler lid or driver side B-pillar. Here is an example:



If the downsized spec is in this list, then you can surely got for it. Of course, you will have to buy the wheels with matching specs (offset, PCD, etc.).

Advantages of 18" wheels:
1. More comfortable ride, reduced road noise - this would be the main benefit
2. Can take a bit more abuse but so much - you won't a get a free pass to be carefree compared to 19"
3. Cheaper to buy if the sizes are easily available

19" wheels:
1. Look great, very difficult to accept the looks of 18" once used to 19" - you would rather learn to drive more cautiously with 19"
2. Much improved handling - especially in demanding situations.

If you don't prioritise the comfort and quietness of 18" and value the improved handling of 19", I would say stick to 19" and learn to be more cautious. Get forged wheels - they don't get damaged that easily.

[museek]

Thanks dear friends for your immediate response.

All my tyre and wheel damages happened in the so called "Expressways" where we all normally maintain a basic speed of 80 to 100 kmph. Even in these roads which appear deceptively smooth there do happen to be an isolated pothole which can really damage the wheel or the tyre.

My stress comes when I am traveling with my family for a time bound programme and this throws all my plans awry. So I think I will work on your inputs and keep you updated.

[123.rishabh]

I am using 245/40/R18 in my S5 B8.5 (Factory Spec for the older model in India) & facing no such issue.
I am attaching a pic of the Placard of B8.5 S5 (sourced online), as per this you can go for 245/40/R18


Don't go for 225, I feel it will be very skinny for such a powerful car with wide rims.
Also what model is it, a B9 or a B8.5

Cheers !

[museek]

Thanks dear senior members for your feedback.

Special thanks to 123.rishahb for his word of encouragement. I have decided to go for the 245/40R18. Will get them in a couple of days and update.

I enjoy driving my S5 everyday. Somehow our roads are not too friendly to our low profile tyres. My S5 is the B9 version and I talked with the Audi service people who are also ok with the R18 size.

[museek]

Dear friends

Had a hectic few weeks. Downsized my alloys to MOMO 18 inches and tyres to Vredestein 245/45 R18.

Done about 1000 kms. Awesome. Softer, smoother and am able to look around and not just at the road surface when I drive. Grip was good. Once got stuck in a monstrous rain while doing a long distance.. good grip, no aquaplaning, while doing comfortable speeds. I am happy with my decision to downsize as I can literally take my car everywhere without too much of tension.

Thanks everyone for your feedback.