Risks of changing Tyre Profile on Small car (from 155/65 to 155/70)

jxharding

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Are there risks of changing Tyre Profile on Small car
It currently has 155/65
I am considering changing it to 155/70 - the tyre is cheaper and more readily available-
BUT i dont want to go mess around with KM and alignment and make the car anything but stock.

Now Tyre Company 1 tried to sell me 155/70 - he said everyone changes from 155/65 to 155/70.
Salesguy says that it will have no effect on the vehicle(this is a firestone/goodyear tyre)

Tyre Company 2 tells me a completely different story :
basically what this site says - you will mess around with speedometers etc (this will then be a Khuma tyre as was
the original brand and size that the car came out with)

Should I change to a more readily, cheaper tyre?
Should I always stick to the original size?
This is subjective but a Korean tyre vs Firestone/Goodyear?
 

ITCynic

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I had to do the same with the car I drive. Apparently the tyres that I would normally use are not imported into South Africa any more.

The original tyres are 145/65 and I was advised by the tyre place that I could use 155/70 instead and the size difference is negligible

Moved the smaller tyres to the front of the car and had the slightly larger tyres put on the rear.

I have had no problems at all.

Also comparing the speedo to my GPS speed does not seem to be a difference between the two.
 

Zuner

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Capture.JPG

i don't know your wheel size but check This out.

i don't see a problem, depending on what car you drive, most cars speedometer reads a higher value than what the car is doing, so this small change would make such a car's speedometer more accurate.
 

APoc184

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Moved the smaller tyres to the front of the car and had the slightly larger tyres put on the rear.

/waits for people to ask if your fuel consumption is better now that you are driving downhill the whole time
 

eg2505

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Same question for myself, whatis reccomended for me?
Cheaper local tire
Currently 165/65 kia picanto
What can I swap to that's cheaper?
 

c3n0byt3

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Should really depend on what car it is.
If the center of mass is already too high this could add some stability issues.
Both because of the slight increase in height and added room to flex.
 

Colin62

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I'm not sure of prices, but a 165/60 is closer in diameter to a 155/65 than a 155/70 is. It's also slightly wider, which can't hurt.

edit:- I don't even know if those are commonly available...
 
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Zuner

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I'm not sure of prices, but a 165/60 is closer in diameter to a 155/65 than a 155/70 is. It's also slightly wider, which can't hurt.

i always buy the widest tires i can afford. after doing some braking tests i'll never go back.
 

furpile

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If you don't want to change from stock size, you have already answered your question. However, I don't think that small difference will make any noticeable difference to the handling of the vehicle. It is best to stick with the manufacturers recommended size though. If you look at a tire calculator like this, you will see that the new size will make the car go 2,6% faster. Most cars have their speedo's set a bit lower by default, so it hsould then be more accurate as has already been mentioned.

Maybe just try a different shop for better prices. According to this, there is not a significant difference between the sizes.

KUMHO
KR26
Passenger Grand Tourer
Size: 155/65 R13 73H
R 545.00

KUMHO
KH17
Passenger tyre
Size: 155/70 R13 75T
R 563.00

Not the same model, but most of the brands are between R500 and R600 for both sizes. So just get the original size.
 

AstroTurf

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My Uno was in an accident and the suspension was kinda lowered when it was fixed.

I put slightly larger (and cheaper) tyres on, never had an issue (besides them not fitting into the spare tyre area so always had a slightly smaller spare in the boot and a spare of the right size at home).

The car felt much better to drive with the bigger tyres. Much softer ride.
 

Skerminkel

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The difference in side wall height is only 8 mm. That is not much more than the tread on a normal tyre. I am no specialist, but I suspect it would make no difference to your car.
If you really want the gurus' opinions, surf over to 4x4community.co.za and ask there. You are bound to get a range of opinions, but at least they will be informed and experienced.
 

Nangi

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145 and 155 tyres? Yho those tyres would kill me for sure. Considering the way I drive I don't think i would ever sign on the dotted line for a car with tyres that skinny, not even for the SO.
 

jxharding

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Its a Chevy Spark, I phoned Chevrolet Head office, they said I must phone Fury Sandton, a technical guy there said it should make no difference. Still concerned, maybe i should just pay the R600 extra for the 4 tyres - but to pay more and not get a Goodyear/Firestone, doesn't feel right :)

but the sales guys are saying that Kumho tyres come standard on all Korean vehicles and its good.
 

Zuner

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Should I change to a more readily, cheaper tyre? YES
Should I always stick to the original size? NOT Necessarily

Its a Chevy Spark, I phoned Chevrolet Head office, they said I must phone Fury Sandton, a technical guy there said it should make no difference. Still concerned, maybe i should just pay the R600 extra for the 4 tyres - but to pay more and not get a Goodyear/Firestone, doesn't feel right :)

but the sales guys are saying that Kumho tyres come standard on all Korean vehicles and its good.

i'd change the size within a heart beat.. that's a very small change and will have little to no effect. tire brand i normally research dry/wet grip and pick the best.
 

krycor

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Usually the main issue is the tyre fitting correctly esp for turning and providing sufficient clearance besides not sticking out of body too much. Car Manufacturer usually will advise and last time i had to do this the tyre place called them up to find out.

PS. you can't go always go wider due to body & rims
 

Beachless

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What car is it and what size rims?

A 165/55 tire might be a closer match.
 

Skerminkel

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Its a Chevy Spark, I phoned Chevrolet Head office, they said I must phone Fury Sandton, a technical guy there said it should make no difference. Still concerned, maybe i should just pay the R600 extra for the 4 tyres - but to pay more and not get a Goodyear/Firestone, doesn't feel right :)

but the sales guys are saying that Kumho tyres come standard on all Korean vehicles and its good.

Rather buy a better quality tyre in the larger (i.e. cheaper) size if you want to spend more money. It should last longer and wear better. Rotate the tyres as per the car's manual.
 
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