Interesting gas mileage find

So just so everyone knows before hand, I'm running ko2s 265/75/16s, 5100s at .85 in the front, trd supercharger, trd pro wheels, trd exhaust.

So I used to have the large chrome trd sport wheels before I got the trd pro wheels. When I had the big sport wheels I was averaging anywhere from 12-15 mpg, very could break past the the 15s though. Anyway, I eventually got the trd pro wheels which weigh like 1/3 of the big sport wheels. So I just started measuring my mpg's again recently and have found that I'm now in the 15-18 range now.. (usually 33% city, 33% highway, and 33% traffic)

Anyway, just thought I'd share for anyone out there with those big chrome wheels!

 

Are you running those same tires on the new wheels as you did on the old wheels? I guess that is unlikely, because I think the Sport wheels were 17". Have you compared the rolling circumference of the wheel/tire combinations? Unless you have taken rolling circumference into consideration, you should consider that the measurement of mpg will be impacted.

 

They were 18 inch wheels. The tire size was different, but the over all diameter and circumference was the same.

 

Was that comparing worn 18" to new 16" tires or comparing manufacturer's specs on diameter?

 

Rubber compound makes a huge difference as well. Some tires stick alot more than others.

 

Unsprung weight is an important factor

 

I think you mean rotating weight. Unsprung weight would also include spindles, tie rods, control arms, etc.

 

Were you running 265/75/16 KO2s before? I believe the stock 17" Sport wheels weigh 27-28lbs, while the 17" Pro wheels weigh 25lbs. Definitely an improvement, but the rule of thumb is rotating mass = 4x static, so if you reduced your weight by 3lbs a corner you are talking 3lbs x4 wheels x4, or about the equivalent of removing 48lbs from your truck. Solid improvement, but nowhere near 3mpg worth.

 

The impact of weight will be limited strictly to acceleration. So while still negligible, it would have more of that negligible impact in city traffic than on the highway, which is more or less constant speed straight line.

 

Like I said before, I had the 18inch chrome wheels as seen in this photo with ko1s 265/65/18, and they weighed a TON compared to the trd pro wheels. The trd pro wheels i have are 16s, not 17s. Could be the supercharger breaking in after 10,000 miles too, I don't know.

 

I should have read that more carefully. The 16" Pro wheels weigh 23.5lbs, and your tire change also saves an additional 1 lbs over the KOs you were running before. I'm not sure the weight on the OEM 18" chrome wheels.

 

Yeah I was looking for the specs online but couldn't find em, but man, they felt like they were made of pure lead haha.