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Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Bigdaveg

A relation recently gifted me a set of old 14inch alloys, my steel wheels were 15inch.

I'm glad to have gone down a size because I've always felt that the 15inch steel wheels and 195/60 r15's were too close to the wheel arch.

Anyway the 14inch wheels have been fitted with 175/65 r14 Conti Eco Contacts, the only downer is knowing what the "normal" pressure should be, I've looked around on the net and can't find anything, the tyres have a max of 44psi.

Can anyone please tell me what the pressure should be.

Any info would be greatly appreciated.

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Collos25

Are these an official Ford Fusion size.

195/60 R15 is the official smallest size.

Edited by Andy Bairsto on 06/07/2010 at 19:53

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Bigdaveg
195 is'nt the smallest, 185/60R14 is.
Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Collos25

Are you are sure they will fit not just physically but the speedo etc.

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Bigdaveg

Apparently when the speedo reeds 60mph I'll actually be doing 56.9 Mph.

This is kinda interesting because when I'm using tomtom my speed is always different to TOMTOM e.g car speedo 60mph tomtom 58 mph, i wonder how many other speedo's are out ??. And that's using the proper specified size tyre ???..

Fuel consumption will be interesting, yes the tyre will be turning more becuase it's smaller BUT, surely the fact that I'm now running conti eco contacts and not cheap Kuma tyres and have lightweight alloys instead of big heavy steel rims should make a difference.

If a speedo error of just 3.1 mph (at 60mph) is the only downer, which in itself is the best anti speed device (as I'll always be below the limit ;-), it's not as bad as I'd first thought.

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Collos25

All speedos should read around 5% fast the reason your TT is reading different it is measuring your speed across the face of the globe via satelites and as a rule is far more accurate although climbing or descending steep hills can cause problems in speed accuracy.

The difference in weight between steel and alloy wheels is not so great and in some cases they are actually heavier due to the amount of metal required to achieve the same strengh as steel.The differnce in tyre manufacturer will not make any difference as you will be concerned.The car will strictly not be street legal because of the size difference regarding the speed.If I were you I would I would stay with the steel wheels and be legal.

But no doubt you think the alloys look better and thats what you will fit.

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Bigdaveg

Can you please tell me where I can find out if it's street legal, given that as you say; All speedos should read around 5% fast.

I've never heard before that Alloys are actually heavier that steel rims, I'm in to mountain bikes and it's well known that Kevlar (folding tyres) are lighter and stronger than steel tyres, so are you saying that Alloys are weaker than Steel wheels and therefore need more metal ?.

I've been onto a web site that says i'm running at 5.2 % too fast, just .2 % off of your statement, how can that be street illegal, the other question is what about all the others that fit bigger tyres, as well as being illegal ?, there also going too slow which means they'll be actually breaking speed limits ??. E.g someone going from a 195/60r15 to a 205/60r15 will be going 2% slower meaning that they'll be doing 61.2 mph instead of 60?, surely that would mean than "alot" of cars on our roads are not street legal ?.

It's also surprising to learn that Tyres such as the Conti Eco Contact are'nt as fuel efficient, hard wearing and better speed rated than the likes of Kuma Tyres, I should've saved myself some money, £15 a tyre ;-)

The wheels & tyres have been fitted in total for just £70, now at that price who would'nt switch from steel to alloys ?. Please let me know where it says about the street legal issue.

Edited by Bigdaveg on 06/07/2010 at 22:05

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Collos25

Read what I said and do a bit of homework.

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Bigdaveg

I don't really need to because someone's already got all the answers and by publishing it they'll not only help me but countless others who have also changed their tyre size.

In the mean time I'll hook up my tomtom and just see exactly how much out it is, bearing in mind that it was 2mph out using the supposed correct tyre size.

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Bigdaveg

Have done a bit of digging and have come up with the following;

Alloy wheels are lighter than steel wheels and are better at dissipating heat, as a result performance and handling may be improved.

Alloys reduce the unsprung weight of a vehicle (rotating mass)

They "may" provide a smoother ride.

On the downside (and "I'm" being honest here) winter may cause finish/surface damage as a result of salt & grit laying and airflow is not as good.

My handling has definetly improved, the car is more responsive, road noise has improved (must be those awful conti's).

Mileage (car odo) is the same, as tested by tomtom & as expected the speedo is slightly out; 55mph instead of 60mph, both my fusion previously and civic recorded a different speed to that of the car speedo, despite using the correct size ???..

This last factor is very interesting, which is why I'd like to thank Andy for bringing it to my attention, however it does create more questions than answers:

how can the correct size wheel and tyre be out

how many cars speedo's are out

does tyre pressure make a difference

How often are car speedo's & sat navs etc calibrated, given that Items of TMEC are normally calibrated at least once a year.

Finally how many cars fail an MOT or how many drivers are convicted of fitting a smaller or larger wheel/tyre ?

Edited by Bigdaveg on 07/07/2010 at 21:20

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Collos25

Lighter wheels can improve handling by reducing unsprung mass, allowing suspension to follow the terrain more closely and thus improve grip, however not all alloy wheels are lighter than their steel equivalents. Reduction in overall vehicle mass can also help to reduce fuel consumption

The above is the first paragraph in Wikipedia.regarding alloy wheels.Born out by the fact that the winter steel wheels for my Saab are lighter than the summer alloys.

You understand nothing about physics ie rotating mass.

You do not understand how GPS works.

You do not understand about wheel offset.

And you certainly do not consider road safety to be important.

There is such a thing as type conformity and if your car was to be invovled in a serious accident the insurance companies look at this matter for loopholes not to pay out.

But please do as you like you will anyway

Edited by Andy Bairsto on 08/07/2010 at 10:41

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - Bigdaveg
"however not all alloy wheels are lighter than their steel equivalents", so a 14inch alloy is going to be heavier than a 15inch steel then ?.

So the knowledge and homework is reliant on what someone else has put onto wiki-pedia ?. Anything OFFICIAL from the DVLA or Police etc ?.

I await the legal confirmation that it is against the law to replace the wheels, when even correct sized wheels give a false reading .......

I suspect there maybe a bit of jealousy, as for road safety being IOSH and CIEH Risk assessed I'd say I have fair respect for safety.

Yep you got me I know knothing about GPS, yep I know nothing about wheel offset and I know nothing about rolling mass, but I'm sure wikipedia could help ;-).

As for TMEC what do you know ?. And how do you know your car, has a correct speedo reading ?.

In my case Conformity has nothing to do with the fitment of alloys, , it's a "personal choice"; I have gone from boring heavy steel wheels with cheap tyres to standard 5 spoke alloys, with conti eco contact tyres, looks have improved, taking them on and off is easier (no need to rip off the ty raps keeping plastic wheel trims on), road noise has improved, handling has improved and fuel ecomony should be improved, all for the measly price of £70.

To avoid this going on, you do your thing & I'll do mine ;-)

Edited by Bigdaveg on 08/07/2010 at 17:12

Ford Fusion - Tyre Pressure For 175/65 R14 Tyres - 1litregolfeater

Stick in 40 all round and you're right to go.

Tyre pressures are a compromise between contact area and feel, grip and sensitivity, comfort and handling. Ignore what the makers say, it's personal preference.