Hello all,

 

I have an Octavia SE 2.0 TDI and tyres' spec is 205/55/R16 91V.

I’m following the manufacturer’s table for the tyre pressure (2.2 bar for both front and rear) but the tyres, visually, seem to be under-inflated. I attach some images for reference.

Any advice?

 

Also, what would be the difference with the ECO tyre pressure (it sounds like a big jump from 2.2 to 2.5)?

 

Thank you,

Yours  don't 'look' underinflated to me.

I have the same tyre sizes and I use the eco pressures of 2.5 bar in order to get better mpg (I hope).

The tyres at the eco pressure also look OK to me , but they are still a bit flat at the bottom . A consequence of having pneumatic tyres.

If you run at the manufacturers recommended pressures, the function rather than the 'look' is met.

Yes, keeping  the correct tyre pressures is important.

3 minutes ago, gregoir said:

Yours  don't 'look' underinflated to me.

I have the same tyre sizes and I use the eco pressures of 2.5 bar in order to get better mpg (I hope).

The tyres at the eco pressure also look OK to me , but they are still a bit flat at the bottom . A consequence of having pneumatic tyres.

If you run at the manufacturers recommended pressures, the function rather than the 'look' is met.

Yes, keeping  the correct tyre pressures is important.

 

Hi gregoir,

 

Thanks for your prompt reply! 

Do you think that having anything between 2.2 and 2.5 would be a good balance between grip and fuel economy? I was thinking of putting 2.3 or 2.4 to all four tyres. 

 

Cheers,

It's up to you and what you want. I don't find any lack of grip running at eco pressures. Experiment within the recommended pressures to get your desired 'look' as well.

Hi. Mine look the same and I check the pressure very often. The reason for their look is the width of your rim (the J number); as they are on the narrow side the same tyre will bulge more that on some wider rims (aftermarket ones are usually wider). If you go too wide (as per modified cars) it might actually push the tyre over its intended width and that would yield the opposite look.

I never know what load I am going to be carrying and to be honest can't be bothered to adjust them whenever I get a different load.

 

As such I run all four corners of my R17's at around 42-43Psi (2.9-3.0 bar) which is about 8Psi (0.55 bar) below the tyre manufacturers maximum pressure (Eagle F1 AS3's XL) ; can't say that I have encountered any problems with doing that, got 23,000 miles (37,000km) out of my last set of tyres on the front with even tread wear.

 

If I am wrong in doing so and in need of an education please enlighten me  

I run 39 psi all Round In Pirelli p zero 19" 235 35 19. If I ran the eco pressure mid to high 40s I believe I hate to think how the grip would be  bad enough at 39 psi. I guess as long as your in the manufacturers limits just run whatever you prefer the feel of.

Eco  pressure of 2.5bar = 36.25bar.

What's the problem?

My tyre man tells me to run my 2.0 tdi estate at 34psi but I find it a bit crashy and solid on 17s.

ive dropped back to 32psi and feels dramatically different, but maybe that’s why I don’t get above 50mpg??

42 minutes ago, gregoir said:

Eco  pressure of 2.5bar = 36.25bar.

What's the problem?

I'm sure you'll have a big problem if you put 36 bar in your tyres 

13 hours ago, gregoir said:

Eco  pressure of 2.5bar = 36.25bar.

What's the problem?

That should be 36.25psi. Apologies.

If you have even tyre wear you are probably spot on. If the sides wear first  then that points to under inflation and if the middle wears first then that's over inflation. That is the simplified version not allowing for all the other causes of edge wear from suspension set ups like camber and  toe in etc. 

On 3/5/2018 at 17:44, BNT1985 said:

If I am wrong in doing so and in need of an education please enlighten me  

 

Isn't 3.0 bar above the recommended maximum even with a fully loaded car? I'd be worried that you're over-inflating so possibly reducing the amount of grip available to you. If your tyre wear is mostly in the centre, then I'd say you are definitely over-inflating. 

As shown in the above photo, 3.2bar is the maximum pressure recommended. I ran my Mark2 Octavia at that when fully laden with camping gear and two push bikes on a tow bar mounted rack. The tyres felt only slightly warm after a long high speed run at 130kph - my rule of thumb check for underinflation.

3.2 bar is the recommended pressure for the *rear* tyres of a heavily loaded car. The photo above recommends 2.5 bar for the front tyres when heavily loaded.

On 06/03/2018 at 17:52, jonathan.tong said:

If your tyre wear is mostly in the centre, then I'd say you are definitely over-inflating. 

Agreed, I would always try to prioritise even wear across the width of the tyre, only problem being it can take a while to work out what is best for this.