First of all, I have been reading on many of the posts regarding wheel/tire combo's and I think I am more confused than when I started.

Please forgive me if this is obvious to the rest of you or if I missed it...I really want some input.

Here are my questions.

1. What is heavier at the same diameter a 20" wheel/tire combo or a 17" wheel/tire combo?
2. Are the 20"s really worse on MPG's, if the wheel/tire combo is the same diameter?
3. Are they harder to keep balanced?
4. Are they much more harsh driving?
5. What do you think about a downsize from a 20" to a 17" wheel and 33" tire.
Thanks for any input.

 

idk everything your asking, but you get a better ride downsizing from a 20" because you have more rubber then b4. as far as weight, it depends on the tire i guess. but if your wanting to downsize, i'll trade you my stock 18s for your 20s =)

 

1. Should equal out and be about the same
2. No, if you keep the same type tire
3. No...just may require a little more weight to balance
4. No
5. I think it looks better with more rubber and less rim

 

Alot of it is personal pref.

Some people, especialy off-road'ers like more rubber less wheel.

The ride can be bad if you go extreme either way. If you go with a 15"-16" wheel and 35+" tires, your tires will be noisy and your ride will feel 'squishy'. If you have 24" wheels and 26" tires your ride with be harsh.

20" wheels with 31"-35" tires is a decent ratio. I like a medium profile tire, I believe it gives the best of all worlds. If you do alot of true Off-Roading then I would go with a smaller wheel and larger tire. But for 90% of everyone else a medium profile tire and a 18"-20" rim seems to be the best of all worlds.

Super low profile tires are for looks and bling and offer very little to performance or anything usefull.

-TheChad

 

This has been my experience:

1. The stock 20's are at least 15 lbs heavier than my stock 18's.
2. The fuel mileage difference is negligible in my opinion (I changed mine).
3. They are more difficult to balance because there is more mass (cheap Pirelli tires) I had to get mine balanced twice.
4. The stock FX4 20's I put on my '10 XLT Screw have a very noticeable and rougher ride.
5. I don't think it's a good idea to go larger than factory recommended tire size but that's just me.

To sum up my opinion, I'm keeping my stock wheel and tires.

 

The tires will be heavier with smaller wheels...and the ride is not as smooth with the 20's because you have less rubber on your wheel

 

That is not 100% true. What if I have 20" wheels and 35" tires? It all depends on the ratio of wheel/tire.

Too much rubber gives you a loud squishy ride and and actually much less efficient. Too little rubber gives you a loud rought ride and can be lees efficient.

Medium profile tires are by far the best ride and efficiency. But you can't judge by wheel size alone. It depends on the tire size going on said wheel size.

-TheChad

 

A lot depend's on the type tire. A "P" rated tire that is 33 inches tall will be lighter and ride smoother then a LT 10 ply tire with the same diameter. Also an all terrain or highway tread will be a lot smoother riding then a mud tire will. A 20 stock Ford wheel and tire assy will not be that much heavier then a 17 or 18 inch wheel with the same type tire but usually a little more rubber will cushion the ride.

 

Your logic doesn't work here. The Pirelli 20's are a bit wider and heavier than my stock 18" Michelins. I weighed them. The 15 lbs heavier reference was because I was including the wheels. The combination weight of wheels and tires is what matters anyhow. The tire also don't ride as well because they are off road tires and the rubber is not as soft as that of a Michelin street tire like come stock on a 2wd XLT verses a 4x4. The Michelins that came off of my truck are rated for 2271 lbs and the Pirelli 20's are rated for 2403 lbs. Plus the Pirelli 20's are almost 1 inch larger diameter.

 

No one with an *** larger than the size of a small frisbee will EVER notice a ride difference between 18" and 20" rims, with tires of the same overall height. No way. Not in this or any lifetime. Ever. Hogwash.

Going from 18 to 20, or 20 to 18, won't affect mileage as long as the overall height remains the same (see tire calculators to see what that means with regards to sidewall profile, and tire width). If you go to a larger overall height, you actually rotate your tires less per mile than the OEM and your mileage may increase as you've changed the drive ratio. If its the same as OEM, like for like.

My 20's at 44 PSI (Pirelli Scorpions) ride fine. I took a trip yesterday, got 12 L/100 kms (about 20 MPGs using US gallons). Almost put us to sleep it was so nice. The ride has a lot more to do with the suspension than the tires. Ford does it right.