[SlavaK]

Hi all. I’m currently running stock alloy rims with 215/70R15 on my 2003 awd and I never liked the look of it.

I’ve been looking for a basic steel 5 leaf rims similar to my 01 cargo Astro (5 lug) and I found this on the web - stock Chevy 255/70R16 with all terrain tires.

So I’m looking for some advice from you who have played with tire upgrades before and my questions are the following:
1. It looks like the only difference to my current tire is adding about 2” to the width, overall diameter should be the same, it it correct?
2. Am I looking for any clearance issues especially on front when turning?
3. I assume there should be no to minimal impact on the transmission since the diameter/radius stays the same, is it correct?
4. Doe’s upsizing the width affects my “immediate stopping length”? I think it will be increased since the same weight sits on larger surface.
5. How bad the MGP might drop?
6. And the last, slightly off topic, why do all Astro spare tires come oversized, 18” I believe?
Your help is much appreciated!

 

[Rod's Trucks]

Hi all. I’m currently running stock alloy rims with 215/70R15 on my 2003 awd and I never liked the look of it. View attachment 287794 View attachment 287795
I’ve been looking for a basic steel 5 leaf rims similar to my 01 cargo Astro (5 lug) and I found this on the web - stock Chevy 255/70R16 with all terrain tires.
View attachment 287796
So I’m looking for some advice from you who have played with tire upgrades before and my questions are the following:
1. It looks like the only difference to my current tire is adding about 2” to the width, overall diameter should be the same, it it correct?
2. Am I looking for any clearance issues especially on front when turning?
3. I assume there should be no to minimal impact on the transmission since the diameter/radius stays the same, is it correct?
4. Doe’s upsizing the width affects my “immediate stopping length”? I think it will be increased since the same weight sits on larger surface.
5. How bad the MGP might drop?
6. And the last, slightly off topic, why do all Astro spare tires come oversized, 18” I believe?
Your help is much appreciated!

Your proposed 16" tire choice is about 10" longer in circumference, so gearing will definitely be affected. That corresponds to about 10% less rotations per mile; therefore, a significant speedometer error.

Go to: Tire Size Comparison

You will need to compare the offset of the wheel spacing, and be sure the bolt patter is the same also.
Rod J
Issaquah, WA

 

[Birdshake]

28” stock to a 30” is going to need a BFH

 

[Mmusicman]

Taller tires with aggressive tread will negatively affect torque and fuel-economy. Too much tire will rub, and will require lift and trimming. Lift may negatively affect fuel=economy too.

Wider footprint increases rolling resistance too.. but slight improvement on stopping.
A little wider is typically ok.. taller is where you usually run into clearance issues.
Wider AND taller will require mods.

One size higher is typically fine (maybe).. moderation is key to success.

As far a mileage losses.. it depends on how tall and aggressive tire is.. and how fast you drive. I'm on Interstate highways a lot.. so I found mileage improvement with HT (highway touring) LT tires.. firm but very smooth. It's what works for me.

Lastly I assume you know ALL 4 TIRES MUST MATCH ON AWD.

 

[SlavaK]

Lastly I assume you know ALL 4 TIRES MUST MATCH ON AWD

I did not know what, but all 4 are matched now. I guess I’ll pass on this option for now. A lot of useful information.
Thank you all!