Wheel thickness: 14x4.5 or 13x5?
 

Greetings fellow ecomodders!

Several threads ago I asked about tire sizes (where I asked if downsizing from 155-65-14s to 155-80-13s) are better (efficiency from less unsprung weight + better at handling rough roads). I got great input and I was pretty darn convinced to try 13s so I put my plan into motion.

My car originally came with 14x4.5j +45 steelies. Tire+steel weighs 10.5kgs / 23lbs and it ticked my curiosity on how much weight savings I'm going to get with 13s.

After several months of searching the appropriate wheel size I hit a wall. I could not find 13x4.5 alloy wheels. Only steels (usually from a Hyundai Eon) were available, it comes with stock hyundai bolt-on hubcaps. Aside from that it looks weird having hyundai wheel covers on my Suzuki I'm just not a fan of the look. So back to the marketplace.

Almost anywhere I've asked there were no available alloys of that size aside from steelies. Only 13x5 alloys are accessible and most of which are from 90s era Corollas, Civics. Fortunately I found r13 alloys from a Daihatsu Charade (they were wildly popular here back in the 90s). Looking up online databases it says that it has 13x4.5j stock sized rims. So I immediately tried to contact the seller, met up (with social distancing of course) and upon inspection I found out that it was actually a 13x5!. Even though I was dismayed it wasn't the correct size I was curious still because it was light at 5.5kgs / 12lbs, and from the looks of it seems aerodynamic.

So I'm at a crossroad here. Since I could not find 13x4.5 wheels would it be wise to stay stock 14x4.5? Or should I take a bite at 13x5 wheels?

If I stayed at 14s I will continue using stock 155-65-14s. Another point to consider is that I'm afraid that going 5" wide 13s would be too wide for 155-80-r13s. I do have the option to going to 165-70-r13s which are the recommended tire width for this according to GT Radial's website using their ETRTO guide. It's almost the same size as stock 155s so I don't have to worry about gearing.

I've also taken into account CapriRacer's study about LRR tires wherein the skinniest tire aren't always the best. In that study I remember a 175-70-13s having equal or better LRR than a 155-80-13 due to less sidewall flexing. I thought about it since I could also apply that to 165-70-13s vs 155-80-13s. But since the tire models used in the study are not available locally I guess it may or may not be the same but its still something to consider.

Any input is appreciated!

Update:
I've double checked the Charade wheels and found it that its 13x5 with an offset of ET40. Original offset of the steelies were ET45. That means these rims would stick out 10mm closer to the fender but would have the same inside clearance towards the suspension components.

You did measure from the bead seat to the bead seat correct?

Correct. It measures 5" from end to end of the bead seats. If i measured it from the outside it measures 6" or 155mm.

Do you know honda insight wheels are 14" and weigh 11lbs? Might be another option to consider if you decide 14" wheels. At that point though it would really just be whether or not the tire weights less since your original setup is 23 lbs.

What year model Insight wheels is this? Do you know what is their width and offset specifications?

99 - 06

14x5.5

+45mm offset

https://www.wheel-size.com/size/honda/insight/2000/

standard tire is 165/65r14, I'm sure you could put a 155/65 tire on there despite the wider rim.

On 5.5" rims it would stretch the 155s to their widest appropriate rim width which I guess would net positive gains in LRR due to less sidewall flexing at the expense being stiffer.

The only caveat I see is that car is nonexistent here in the ASEAN market. I don't remember seeing one of those much less the rims.

And 14 inch trailer wheels are about 12.5lb

How thick? Those things are damn light. Shame they're not much to look at.

First, I am of the opinion that the make and model of tire matters so much more than tire size, that changing tire size isn't worth the cost.

But to address the issue you've raised, a 155/80R13 has an allowable rim width of 4 to 5".