Finally upgraded to 155/80/13s after several years of reading and lurking here

[leoblack9]

After an unfortunate tire blowout with my old 155/65/14 tires I finally had a chance to apply what I've learned over the years from this forum.



Autopsy report: Huge pothole + 5 year old tire (tons of microcracks in the sidewall). The pictures speaks for itself.


Inevitable event here in Philippines where roads are crap.


I already bought a 13x4.5 steel rim a year ago in anticipation for this upgrade. Tire selection is very limited. Other tire options were GT Radial Champiro Ecos and CST Marquis MR61. I opted for Thunderer since its the freshest tire I could find (DOT 2522) and I didn't have the option of waiting.

Fitted with Thunderer R202 city tires. Made in Thailand.


Installing the new tires. It raised the ground clearance an inch or so.


I picked this style hubcap because its the closest thing to a flat surface that's available in the market. The 90s rounded style also fits the suzuki alto's curves/edges.


Tread pattern


Suspension geometry should still be stock. Its absolutely perplexing why India gets the 155/80/13s as stock with these vehicles while the rest of the world gets the ****tier 155/65/14s. Still same tire width, offset (+45). New tires look absolutely chunky on my car its cute to look at.

Post-upgrade thoughts:

• Speedometer is now dead accurate to my phone's GPS speedo
• The ride is supple! I thought i was riding a pushcart with my old tires.
• Acceleration took a hit. Engine revs happier more with older smaller tires. I was expecting the lesser unsprung weight would offset this.
• Fuel economy took a hit (as expected). 1 tankful (35L) on old tires: 440km, new tires: 410km
• New tires are of softer compound. Old Acceleras have 400AA treadwear, New Thunderers have 300AB. I expect fuel economy goes up as rolling resistance goes down with wear.
• Tires produce a characteristic hum above 60~80km/h. I guess these tires are probably made for low speed city driving. Driving in the wet the tires feel planted. Braking is decent.

[oil pan 4]

Imperial size 13 and 14 tires are pretty much dead wheel sizes in the US. Everything has gone bigger, a lot bigger.
Tires need to break in for a few thousand km before they give normal fuel economy. I have seen about a 20% hit going to new tires.

[Piwoslaw]

Noice, should lower your revs, especially on the highway.

I wonder about the max pressure for the new tires?

[leoblack9]

Originally Posted by oil pan 4

Imperial size 13 and 14 tires are pretty much dead wheel sizes in the US. Everything has gone bigger, a lot bigger.
Tires need to break in for a few thousand km before they give normal fuel economy. I have seen about a 20% hit going to new tires.

True. Though 175/70/13s should be the last bastion of 13 incher tires there I bet.

You're correct on the tires, I've driven 700kms and the fuel economy gets better as the initial layers get worn off. I noticed with half a tank that I've already driven as much as the old tires, which got me excited.

Noice, should lower your revs, especially on the highway.

I wonder about the max pressure for the new tires?

I use manufacturer specified 36psi (loaded pressure) all around. I still want a balance of comfort and economy. And there are no long stretches of highway here unless you go out of town. Its mostly down to city driving. Night driving is another story though. I can cruise all around town with 4% lower rpm than before.

edit: oh i reread your comment. its max 44psi on the sidewall.

[Piwoslaw]

Maybe you would like to experiment with 40 psi, instead of 36? It's the MAX minus 10% rule.

With taller sidewalls you are still absorbing morethan with the previous, lower tires.
Plus, as a few tire specialists have told me - A bit more pressure better protects the rim from potholes.

[cRiPpLe_rOoStEr]

Originally Posted by leoblack9

True. Though 175/70/13s should be the last bastion of 13 incher tires there I bet.

Anything other than Chinese nowadays has been either 165/70 or 175/70 while 145/80 and 155/80 which used to be quite common in my country have been a PITA to find. Odd enough, it's still easier to find those measures in neighboring countries where Asian cars used to be more common than here prior to the '90s. Uruguay and Paraguay for instance have been the way to go for 13" and even 12" tires.

[leoblack9]

Maybe you would like to experiment with 40 psi, instead of 36? It's the MAX minus 10% rule.

With taller sidewalls you are still absorbing morethan with the previous, lower tires.
Plus, as a few tire specialists have told me - A bit more pressure better protects the rim from potholes.

I was running 36psi on my old tires before the blowout. With that tire pressure the 155/65/14 were hard as a rock.

On the other hand 36psi is plenty comfortable on the new 155/80/13s. Its also recommended by the door labels for fully loaded configuration.I did try 40psi but it seemed a bit harder now (closer to the 14s in feeling) so went back to 36. I would love to do max psi but I have to balance it out with the terrible roads and potholes I have here.

Originally Posted by cRiPpLe_rOoStEr

Anything other than Chinese nowadays has been either 165/70 or 175/70 while 145/80 and 155/80 which used to be quite common in my country have been a PITA to find. Odd enough, it's still easier to find those measures in neighboring countries where Asian cars used to be more common than here prior to the '90s. Uruguay and Paraguay for instance have been the way to go for 13" and even 12" tires.

Even in the Philippines 155/80 is now very hard to find. 175/70/13s are more common. 175/65/14 is the most common sedan tire here since it's used mostly by taxis and the most popular sedan around--Toyota Vios.

[cRiPpLe_rOoStEr]

Originally Posted by leoblack9

175/65/14 is the most common sedan tire here since it's used mostly by taxis and the most popular sedan around--Toyota Vios.

That tire size in the Brazilian Vios was only for the spare tire, with a diameter smaller than the 185/60 R15 tires fitted to it, but the Etios had the 175/65 R14.