[devsoftech]

I wish to downsize my 2008 SX4 ZXi 205/60/R16 (JK Vectras - 20,000 kms done) to 205/65/R15 (Michelin Primacy LC) done.

Reasons:
1. 205/65/R15 sidewall will make ride more comfortable
2. Overall tyre diameter error less than 1% (tolerable)
3. GC falls by 5 mm (190-5=185 mm) still good, and inviting lesser body roll
4. 114.3 5 lug alloys are available
5. 15" is not an issue for brake rotors on front3. Cheaper to buy 205/65/R15 tyres than R16 ones

6. Money
[15 inches]
PRIMACY LC 205/65/R15 = 5500*5 = 27500
5 alloys = 19000
Total: 46500

[16 inches]
PRIMACY LC 205/60/R16 = 9000*5 = 45000

So effectively 15" downgrade will be in the range of 32K-37K (with buy back). Or otherwise still a (next) one-time investment.

I would be interested in buy back, and I'm expecting 10-15k for 5 OEM alloys with 4 JK Vectras having almost 50% usable life in it (is it a sensible ask, if yes, where can I go in bangalore ). One of the JK's (out of 5) has a sidewall damage and is useless. I do drive on rough terrain on weekends (almost 10 kms) - monthly max of 100 kms, and my priority is good driving comfort.

I had zeroed in for Conti CPC2 205/60/R16 but I feel my profile should give me better ride quality. I'm not sure about FE / acceleration side effects. Please enlighten !

For long drives on highways and inter cities (4 times a year) do you think R15 is a good choice ? Awaiting feedback / inputs

Any one having clue of PCD of alloys of 15" Honda Civic / Innova. Both these cars support 205/65/R15, so I'm confident that my downgrade will still not compromise on handling.

[GTO]

Originally Posted by devsoftech

I wish to downsize my 2008 SX4 ZXi 205/60/R16 (JK Vectras - 20,000 kms done) to 205/65/R15 (Michelin Primacy LC) done.

I'm going to give this a . Most people are always talking of tyre upsizes, but few realise that a downsize could benefit their usage. I remember recommending a downsize from 16 -> 15 inch wheels to owners of the C Class, Accord & SX4 (all cars suffer from stiff low speed ride).

You broadly have two options:

- Koni FSD Dampers : They basically have variable damping and, from what I hear, substantially improve low speed ride quality. The minute your driving style becomes more aggressive / faster, they stiffen up (to aid handling). Yet, at intown speeds, you will notice an improvement in comfort levels.

OR

- Downsize to 15 inch wheels. You can't go wrong, the difference in overall diameter is marginal & within acceptable levels.

Originally Posted by devsoftech

Any one having clue of PCD of alloys of 15" Honda Civic / Innova. Both these cars support 205/65/R15, so I'm confident that my downgrade will still not compromise on handling.

Civic PCD = 114.3

[patil]

Hi,
Its very strange that you are planning for a downsize. Further I am surprised to know that there is a difference of more than Rs. 4,500/- between 15' and 16' size tyres. So far as I know the price difference between 15' and 16' tyres should not be more than Rs. 1,000/- to 1,500/-. Check prices of other brand tyres and verify.

Moreover if u want a better ride quality you can go for higher profile tyres in 16' size only. My opinion is that the biggest advantage and usp of the SX4 is its ground clearance and if u reduce it there is no point. Considering the present state of roads anywhere u always tend to pass over a bad strech of road wherein higher the ground clearence better.

So think over and decide.

[devsoftech]

GTO, thanks for the morale boost and about the Koni Shocks. I won't call 5mm (still 185mm) of GC loss a big deal (which I'm losing anyway keeping tire pressure at 28 psi). I still will not hit most of the breakers. The prices are the comfort range of tyres and all compatiable 16" comfort tyres range between 7000-9000. Since my equation deals only with michelins, I am able to do price justification. However there would be atleast 2000-2500 price difference in 15 v/s 16 inches. I have compared for michelin, bridestone, conti (15" out of stock) and yokohama. (Not considering others) - My expenses are worth provided I get a buyback of atleast 2000 per tyre including rims + tyres (which is a fair thought) as 16" alloys cost atleast 5k-6k in market. This 15" thought came into my head after driving an innova. 215/60/R16 (camry tyres) is a definite higher profile with more sidewall (and more comfort), but I'll have skewed speedo readings. Steering is definitely harder and also a drop in FE. Though slight compromise in handling I personally feel 195/75 R15 can do wonders.
I have test driven a polo base version, SX4 base version, Zen estilo base version and all these cars were comfortable when I have taken test drive of these. Reason: These lower models tyres are so called "skinny". When I bought SX4 Zxi, I took time for me to figure out that these "lower profile" stuff (and obviously JK) are to blame. I do not put my car to extremes where handling needs to be 100/100. ANHC with 15" and lesser sidewall ratio is a harsher ride than its previous generation. SX4 can do wonders (comfortwise) if the right tyre is provided. Smaller tyres (not necessarily rims) help in quicker acceleration too. I have never seen comfort (i started with better handling), so its time for me to enjoy some comfort

[NOS Power]

@devsoftech, this is a win win situation for you. You are investing in both comfort and handling at the same time. The Michelin's will be a much better replacement for the Vectras and at the same time increasing ride comfort due to the higher side profile.

16" tyres are a rarity and do command a premium in the aftermarket tyre industry. For the price you are getting the wheel and tyre combo in 15's its a great deal.

[kpzen]

Interesting and a very logical idea.

Innova or Civic 15" rims should work for SX4.

Min. difference between 15" & 16" tires is 2k & in 16" you don't have much option as only 2 cars (SX4 and CRUZE) come with 205/60-16 tires.
Are you sure about the price of 205/65-15 Primacy LC ? I think its around 6k.

[devsoftech]

In Bangalore, Tyre Plus retailer quoted 5500. There are some shops quoting upto 5800 per tyre. That's the max for 15".

Now I have another question - 6J alloys or 6.5J alloys. 15" are common with 6.5J, my hubs can accomodate 6.5J and I think the offsets should be just fine (existing 205 does not touch wheel wells). What is the difference in ride quality if I opt for 6J v/s 6.5J. Also Honda alloys have a waiting period of one month. 4 alloys asking price is 22,000 - so I'm dropping honda alloys (but rather go for cheaper 5 spoke alloys from some reputed brand)

[devsoftech]

The mission was completed today :-) swapped 4 wheels with 15" Xtreme-make Neo Wheels (5 lugs X 114.3 PCD, 65 offset, 6J width) and Primacy LC. Got the install done at Tyre Plus with new wheels balanced and wheels aligned. According to them GC increased :-( as they have to raise the car slightly while pulling out the tyres. Pics will follow up in broad daylight tomorrow. Test drive was a pleasant surprise. Noiseless tyres and I could actually hear my suspension and fenders making some cluck-cluck sound (How to fix them, HELP !) over breakers. Acceleration remains same and same "knock' feel was there while shifting gears. Braking is also same and handling is marginally better. Wheel spin in first gear (while releasing clutch/accelerating aggressively) is just like J K's (so may be same grip) and plain road feels very smooth. I think I'm feeling engine vibrations more. I have not mentioned it earlier, but my cars were damped 3 weeks before on all 4 doors on each side using 8 dynamat sheets (can discuss in a different thread). (OT) The next level I'm looking at is isolating engine vibrations, improving low end RPM torque and damping engine noise slightly more.

[kpzen]

Great. Now pls post some pics.
GC would have increased for sure but what do you mean by "they had to raise the car slightly while pulling out the tyres"?

How much did you sell the Stock alloys for ?

[devsoftech]

(Read as) While putting new wheels, they had to lift the car.

I haven't sold the old wheels and old alloys and plan to use it for bad road trips. I somehow was not convinced to sell. Alloys look so graceful. I want to keep my options of having both types of wheels based on driving need. I have plans to get motorised jack or hydraulic ones and that will help me in quick swaps (though this will not be a frequent activity). If tyres collect dust in 6-8 months, I will sell for sure.

Install followed up with pics below:

[amalji]

I had also done a tyre downsize on old ( 99 model ) Maruti Zen and I would recommend this mod for anyone using 13" tyres for Maruti Zen

Old tyre size - 145/70 R13
After the mod - 145/80 R12

The advantages -

• Rim doesn't hit the road as frequently
• Ride comfort increased many fold!
• Better ground clearance

Brand of tyre used - Michelin XM1
Rim Used - Aura 12" Alloys

Reasons why I switched to alloys

• I wanted to go for tubeless tyres. A bent rim is always going to be a headache. Alloys won't bend
• And ofcourse the looks

And the only disadvantage was the car's handling decreased slightly. That was ok, because Zen's handling is very good to accommodate that slight decrease.

[devsoftech]

Posting a followup to this thread after 10,000 kms of driving post upgrade:

Observations/Issues (at 30,000 kms):
1. Engine is no more silent as it used to be (concealed due to tire noise)
2. Suspension noise while going over breakers is evident. Good for me as I got it serviced (greasing etc) on time.
3. The alloy of my choice was 37mm offset. SX4 OEM is 50mm. However, the new tires were slightly protruding out. (I have no clue why this should happen).
4. At 30,000 service, the stabilizer bar connecting rods (front suspension) were replaced. Not sure if it was due to offset changes.
5. Body roll is lesser.
6. Yeah, I did scrape my car at some familiar roads where I used to rule earlier by not braking. Now I do a honda city there

What's my (updated) advice:
1. Swap with a CIVIC OEM alloy, or, get a 15" VXI steel rim. Atleast the PCD and offset is guaranteed. You can get steel rims for cheap prices (used-600 to new-4000 for 4 rims).

2. SX4 ZXi crappy JK Vectra's cost 6300 (as per Pratham motors). It makes a lot of sense to switch to more comfortable 15" inchers (at 5200 per tyre).
You can even trade in the stock enkei alloys for 2000 and tyres for 500-1500 and be happy with 15" tyre + 15" steel rims.
Indicative new cost (worst) = 5200+1000-2000-500 = 3700
Next time you have an issue with the J K's, please get rid of it

After that (once tyres are worn out) - u still can buy cheaper 15 inchers.

3. Along with this update, you can also go for 10mm suspension drop. The 2010 onwards VVT Zxi has a drop of 10mm in suspension due to changed coils and shocks. All you have to do is just ask for "TYPE 3 ZXI" suspension.

Suspension drop will cause your car to drop to a GC of 190(stock)-10(new shocks)-8(tyre downsize diameter changes)=172mm.

If you are curious why I spoke of suspension changes, I would suggest you to go for a VVT Zxi TD, the ride quality will speak for itself. The springs are setup on the softer side.

4. I drove on all types of terrain - Michelins did not get any bulge. It could be because my tyre load index is 94 and more flex in sidewall (max 670 kg per wheel). The so called hard JK's had ended up with sidewall cut and cracked rubber on such roads.

5. Audio system sounds so much better. besides I don't even feel like sitting in a stock Zxi. the noise just kills me.

[sunit]

I own an SX4 ZXI (not the new VVT) which is about 2 years old and run close to 30,000 kms. Every now and then I am tempted to upgrade to a more comfortable car. But the feeling of bring debt- free very soon keeps me going. I would to love to keep my Sx4 for as long as i can if I am to fix some of my biggest pain points.

I live in Indiranagar, Bangalore and work in JP nagar which is roughly at a distance of 10km. It's not that big a distance but boy it's one hell of a ride. I am perpetually taking shortcuts to avoid the main road traffic but it just makes my commute even more hectic. And as you might all know the SX4 ride in slow speeds isn't the most comfortable. I'd love to move to JP nagar but my wife and kid are well settled in Indiranagar so that's not an option. So, I am willing to do anything to make ride a little more comfortable.

And today here's what I need help with:

1. Should I upgrade the stock JK Vectra to Michelins? I've read on some of the threads that all the credit to the bumpy ride goes to the stock tyres. I am guessing the costs involved is upwards of 9k a tyre. It is a huge expense so I want to know if it's an investment worth making.

2. The other factor that makes my ride painful is the steering- it's way too stiff. It's always been like that but off late it's got worse. The Maruti guys haven't been able to help - each time they tell me to get my wheel balanced / aligned but it hasn't helped at all. Is it got anything to do with the larger tyres that come with the ZXI or would better tyres help this cause as well? Any tips on optimising this?

3. Is it too early to getting my suspensions changed, what's the ideal time to do that? Let me know.

Any other tips or advice would be of great help. Really looking forward to hear from other SX4 and longer term car owners.

Thanks

Sunit

[SRK]

Do not change the suspension as of now, would be expensive.

Try upgrading to new tyres.
May be you could go in for some high profile ones. Experts could help better here.
An upgrade to lighter alloys might also help to keep the overall mass down.

As for the steering. Get the alignment done and tyre pressure checked.
Worse case could be that your power steering unit has gone bad.

[aaggoswami]

1) If the alignment has gone bad, then it would be reflected in :
a. Car pulling on one side.
b. Uneven tyre wear.
Along with a lack of high speed stability, car pulling on one side is a very good indicator of alignment not proper.

If your Power steering unit is gone, then it would be displayed on the dash with a small warning light.

My guess here is that in order to set the things right, they have overtightened something that is causing the steering to stiff.

2) The VVT SX4 had softened up suspension. As your dealer if it can be a direct fit on your car. If yes, you can consider it, but before doing so, TD VVT SX4 which would give you a better view about how much the ride has changed and are you comfortable with that or not.

3) Keep the tyre pressure around 3-4 PSI lower than what is recommended, this would help you in ride quality, but FE would be hit. At the same time as its city run, it wont make a very big difference.