Gear ratio/ tires.

Madcap · August 17, 2006

I could not find in my manual what gear ratio I have.. Does it say?

Anyway I want to find out my gear ratio as well as what larger tire I can put on without effecting the ride too much. Obviously it has to fit in the wheel well without rubbing and I still want a fairly smooth ride.

My current tire is a 245 70 R17 Ameritrac Generals. My thoughts is that I could go with a 265 70R 17 or possibly a 265 75 R17 if that is even a correct size. What are your thoughts about tire sizes guys because I am a noob when it comes to trucks. My old Silverado was a lease but now that i'm buying this one I really want to upgrade things and I have to learn somewhere.

I guess it would help if I said what truck I have Its a Green Metallic LT1 2006 1500 2WD Crew cab w/ a 5.3L V8. and I love it!

Hopefully I didn't ramble and I would appreciate anyone advice,opinions on what size tire I could upgrade to. Thanks!

95Sierra2500 · August 17, 2006

I'd suggest that, if you're looking for sizes, head over to www.tirerack.com and put in what you're looking for. If you're just going up a little bit it shouldn't be bad, but if you're going up sizes ALOT then you may need to swap gears...

2004GMC1500CC · August 17, 2006

I could not find in my manual what gear ratio I have.. Does it say?

Anyway I want to find out my gear ratio as well as what larger tire I can put on without effecting the ride too much. Obviously it has to fit in the wheel well without rubbing and I still want a fairly smooth ride.

My current tire is a 245 70 R17 Ameritrac Generals. My thoughts is that I could go with a 265 70R 17 or possibly a 265 75 R17 if that is even a correct size. What are your thoughts about tire sizes guys because I am a noob when it comes to trucks. My old Silverado was a lease but now that i'm buying this one I really want to upgrade things and I have to learn somewhere.

I guess it would help if I said what truck I have Its a Green Metallic LT1 2006 1500 2WD Crew cab w/ a 5.3L V8. and I love it!

Hopefully I didn't ramble and I would appreciate anyone advice,opinions on what size tire I could upgrade to. Thanks!

<{POST_SNAPBACK}>

Manual won't show what gear ratio you have, the glove box will show you the codes for you truck which you can decode.

As far as tire sizes go, I had the stock 245/70/16's on mine and put 265/75/16's on it and now have 285/60/18's on it with no rubbing or any issues. You can fit any size that a stock SS can fit since everything is the same.

Madcap · August 17, 2006

Hmm. so everything is the same as a stock SS.

Wouldn't the 285/60/18's stick out allot and kick up allot of mud? I'm suprised I could go that high with no rubbing issues or gearing issues.

2004GMC1500CC · August 17, 2006

Hmm. so everything is the same as a stock SS.

Wouldn't the 285/60/18's stick out allot and kick up allot of mud? I'm suprised I could go that high with no rubbing issues or gearing issues.

<{POST_SNAPBACK}>

All I know is that mine has no issues at all. You can look at a picture in my profile of what they look like. I have 373 gears and don't have any problems if you have 323's (and I bet you do) you may have some issues, but it isn't THAT drastic of a change, unless you reguarly tow near the max for your vehicle.

ZZebes · August 17, 2006

i'm guessing 3.42's but check the RPO

Madcap · August 17, 2006

Sorry but what is a RP0? I did check the glove box at lunch and I couldn't decode anything that might of been my gear ratio so I need to figure out how to do that.

How many different gear ratios will a Silverado have? And where does the 3.42 rank in the midst of them.

jwalker · August 17, 2006

I believe that there is a formula that a guy can tell what the final drive ratios are when you increase tire size. Does anyone know by chance?

lowrider · August 17, 2006

If your looking for a wider tire, and wanting the same OD, thus not messing with the gearing, seedo and etc., a 265/65/17 will fit the bill. The 245/70/17 and the 265/65/17 have the same outer diameter. Also, the 265/65/18 size is easier to locate than the 245/70/17. When my Generals go, I plan on going with the 265/65s.

Also, and this is just my opinion, the shorter the sidewall height (within reason on a truck) the better the handling. Look at what has happened to the aspect ratio on automobile tires. Again, IMO, it looks silly to see trucks with 16 or 15" wheels running around on tires with humongous sidewalls. I think the stock 17" wheel (I have GMC polished alloys) look just about perfect with the 245/70s, and I want to retain that look.

Lou

johnquest · August 17, 2006

Run the VIN number of your truck at this site. There's a guy there who checks GM vin numbers for you. He responds the same day you post with the complet vehicle history and build codes from GM. Go to dieselplace.com and look for the forum called "vin check."

It's pretty cool. You'll also get any recall information on your truck, claim history under warranty, etc.

JQ

lowrider · August 18, 2006

Sorry but what is a RP0? I did check the glove box at lunch and I couldn't decode anything that might of been my gear ratio so I need to figure out how to do that.

How many different gear ratios will a Silverado have? And where does the 3.42 rank in the midst of them.

<{POST_SNAPBACK}>

RPOs are listed in your glove box door (inside). Below is link to 2006. Look down to those beginning with a "G". All late models are similar.

http://gm-trucks.com/home/content/view/186/30/

Lou

wink05 · August 18, 2006

Just a suggestion. you might want to check out one of the online tire size calculators, such as www.1010tires.com and enter your stock size and compare to other sizes you're considering to determine the difference in circumference, speedometer error, etc. This is especially helpful if you're considering going from a 17" to 18" or larger. Hope this helps.