Cooper CS4's on Tiguan

[Arctra]

I did have to put a new set of tyres on this week - the front ones were well worn. I put on Cooper CS4s. I did notice a drop in the economy for the trip to Wagga - it went from an average of 5.4 l/100 to about 6.3. Not happy. I may move them to the rear, wear out the old back tyres and put on some different ones - with a little more research. I was amazed at the difference in economy just from the tyres.
Any advice on tyres would be welcome.

Oh wow, I'm so glad you mentioned this! I have been considering the Coopers. Would you mind taking a picture of them on your Tig for me so I can see what they look like?

I'm surprised they affected your economy that badly, but then again, they are not dedicated highway tyres like your originals were. So I guess it makes a bit of sense.

[jimbomort]

Yes I'm surprised if they'd make that big a diff too, I've commented at the thread source (newbies corner), I wonder whether part of the problem is a change in running tyre pressure or somethign else.

By somethign else I mean a headwind that day, bad batch of fuel, different driving (higher speed/traffic) or the like. I'd be checking out other explanations further and seeing what happens with more experience on those tyres before assuming the tyres per se have that big an impact on fuel economy.

However if they are the problem, thats a big difference and good to know.

[Transporter]

It is not that unusual that when you replace the tyre with different brand you use more fuel. When I replace original Bridgestone tyres on our Forester at 50,000+km with Pirellis Scorpion we started to use 1L more fuel straight away and it went back to 9.2L/100km when we put the same Bridgestone tyres back on, some 40,000km later.

[Tedhaggie]

Aleft feid comment

THe general info on a 215/65R16 trye has the following

Calc radius 344mm
Static radius 313 mm
Dynamic Radius 333 mm

THe info on the Bridgestone HP gives a calc of 343
The CS4 344


I suspect the the CS4 is a much stiffer tyre and and the dynamic radius Could be 6-8% higher.

THis affects fuel consumption in 2 ways
1 your actually going 6% faster = more fuel probably of the order of 10%
2. your actually going 6% further -

So apparent impact on Consumption would be 16.6%

ie 6% + 10% + (10% X6%)

if you have GPS a speed comparison with the digital speedo might answer my question

[NZTiguan]

Running different tires front and rear may be an issue as well with a 4 wheel drive system such as the Haldex ? I know it has an effect on all the off-road settings and is actually shown as a "no no" in the manual !!

Cheers

[Tedhaggie]

I think that it would have an inpact the haldex. BUT the haldex should be able to hande these variations otherwise the spaceaver spare would be out of the question, but I think the speed limitation in that case is to do with the tyre construction not the HALDEX

Also if its just difference in tyre efficiency it should show as heat in the tyres
a 10% risein heat dissipation would cause as significant rise in temperature

[NZTiguan]

I think that it would have an inpact the haldex. BUT the haldex should be able to hande these variations otherwise the spaceaver spare would be out of the question, but I think the speed limitation in that case is to do with the tyre construction not the HALDEX

The space saver is "supposed" to be the same diameter as the original tyres AND is speed limited isn't it ? I do realise that this may not always be the case (same size) but you don't run a space saver at highway speeds for long distances. My guess is that two different sized tyres (front / rear) "could" cause all sorts of potential issues for Haldex or any 4WD system. Just a thought though, I'm not certain of any of this, though I certainly wouldn't be running two very different "pairs" of tyres on my Tig as I know that it effects the off-road system if nothing else.

Cheers

[Tedhaggie]

Having had to unwind a locked cruiser ute because some left it it 4WD on the Highway .

I am inclined to agree - BUt then you have to think if you have a tyre failure. you should replace the set if wear is greater than 30%? to comply.

[T&M]

Aleft feid comment

THe general info on a 215/65R16 trye has the following

Calc radius 344mm
Static radius 313 mm
Dynamic Radius 333 mm

THe info on the Bridgestone HP gives a calc of 343
The CS4 344


I suspect the the CS4 is a much stiffer tyre and and the dynamic radius Could be 6-8% higher.

THis affects fuel consumption in 2 ways
1 your actually going 6% faster = more fuel probably of the order of 10%
2. your actually going 6% further -

So apparent impact on Consumption would be 16.6%

ie 6% + 10% + (10% X6%)

if you have GPS a speed comparison with the digital speedo might answer my question

X2


...but not everyone will be moving from Brigdestone HP's to eg. Coopers so there will be other slight differences as well. Not to mention worn tyres vs new diameter.

I'm actually looking at going to a 215/70x16 when we are due (or something similar to that). Slightly better clearance and we can get the LT (light truck) variants in these so will be MUCH MUCH better and stronger on the dirt.

[Krautlover]

I'm in the same boat as TiguanJo. Replaced the front Bridgestone H/P's with a pair of Cooper CS4 (It wasn't by choice as I couldn't locate replacement H/P's).

It's been a week since the change and I haven't noticed a change in fuel economy. Will watch this more closely now though.

I've found the ride to be a little harsher, I guess due to the stronger compound, but otherwise they seem like good tyres.