I am wondeinrg If i downgrade form 17" to 15" if it will give me worse, better or same MPG..I travel 50 miles coming and going to work and right now I get 19.5 with my stock rims and tires

Eventually I would like to get bigger tires and if smaller rims are the best bet for MPG's whay would be the best size tire to go with it?...i dont want to go too big ..I believe 35's would be too much for what i want to do

Any thoughts?

Alfy

 

According to
http://www.caranddriver.com/features...sted-tech_dept

You should see better mileage.

 

I feel it depends, a low profile Volkswagen wheel and tire is much different than an off road tire.

I think you need to look at the weight of a 33x12.5x15" (steel?) wheel , and look at 33x12.5x17" wheel (stock alum?), also the tires since the 17" will have 2" less of thick sidewall.

Also consider the price difference between rims you already own and buying another set..

 

There are so many variables involved that there is no accurate way of knowing.

Just some variables:
Rolling resistance of tire v tire
change in overall height
change in overall weight
tire growth with heat, pressure, centripetal force

19.5 is very good for a Wrangler JK. I'd be happy with that. Besides that any gains you get from this won't begin to offset the cost of the swap; even if you buy take-offs.

 

Trying to decide the same thing for myself only not for MPG's just for the cost of rims and tires themselves.

15's are WAY cheaper with more tire choices but Im not sure if the weight of the steel rims and more rubber will = that of 17" aluminum wheels and less rubber. I know on my bike (yes i know its affected more on 2 wheels) the less reciprocating mass the better the bike handles/responds and is less stress on the engine/suspension and brakes cause it takes more power to get going/stop the heavier wheels.

Also read through some articles/threads on here about pro's and con's and thought I decided to stay with 17's but im not 100% sure

 

I am certainly no rocket scientist, but it seems to reason that for every rotation, the larger the tire the farther you travel. So go with 40’s. Yeah I know you have to take into account the weight of the tire.

 

All great info fellas TY

MPG is my main reasoning here...I love my 19.5 rating and would like to keep it close to it as much as possible

I am thinking some 15" crager soft 8's.. What would be the biggest tires I could use on the cragers without having to change much? I.E gearing, spacers, and lift

Alfy

 

Sorry but you are getting better mileage than about 90% of the peple on this forum. Rotating mass, load on the engine, higher in the air column, etc, etc add up quickly to deteriorate mpg when you start to modify things. Comes with the territory.

 

Thats what i was afraid of... I wanted to combine decent milage wiith the offroading capability

Nothing too radical on the crawling side , but something that would get me by on some decent trails


Alfy

 

We could get that, if they'd only let us have a diesel here in the states