Hey everyone, i'm curious on if anyone has noticed a significant drop/gain in gas mileage after changing rim sizes.

 

i was just thinking about this, and wondering if you are worried due to the extra or less weight, i dont think that will make a noticable difference. but what i think will happen is this, i am not sure if the odometer is set to a specific size of wheel to revolution of wheel factory setting, or if it goes by the actual revolution of the wheel on the car. if you have stock 15, and switch to 17, the the wheel would be making less revolutions per mile, showing you drove less miles than you really did, and also showing a drop in gas mileage. when in reallity your still getting the same milage as the 15, and vice versa if you down sized, same thing would happen, just to the opposite effect. anybody else have any info to settle this,or personal experience perhaps.

 

well, the stock Fit Sport model runs on 15's. The optional rims are 16"s. I'm currently running on 14" snows and i'm thinking about going 16's. I'm just curious on if i shoudl be concerned about gas miliage

 

Some say there will be a difference. Im saying there isnt. If anything 1-2mpg but that can be driving habits and weather. Maybe 15's to 17's. With the correct size tires it shouldnt be a problem.

Ive ran 215/50/15's, 205/60/14's, 225/50/15's, and right now 195/50/15's. 5 different sets of wheels and Im almost at 20,000miles. All my wheels have been different weights, the 14's being the lightest of course. Going from my Eurosports (blue wheels) to my 14's I didnt notice a difference in MPG.

I did notice the car seemed more lively though; due to the weight differences.

 

there are only three things that will affect your MPG in regard to wheels/tires:

1. weight. the weight of the new wheel and tire combo as a whole
2. diameter. this is not the rim size, but the size of a rim and tire. If you are running a 205/45/16 tire, your overall diameter (rim and tire) is less than stock. a nice calculator is available here: Wheel / tire size calculator / comparer - RIMS-N-TIRES
3. rolling resistance. this has to do with the tire, obviously wider tires will create more friction and reduce gas mileage. Tire compounds play a role here as well.

As long as you are adjusting the size of your sidewall with the increase in wheel size, and keeping overall weight low, the only thing that will affect your MPG will be rolling resistance--which will be a 1-2 mpg difference.

 

methodbasic is correct. As long as you stay with a lighter weight wheel and the correct tire size you are going to be fine. Some tires do use low rolling resistant compounds now. You do want to stay with the same overall diameter for the tire.
If I can help let me know.

 

i recently went on a long road trip a repeat of a long roadtrip I took last year at the same time on the oem dunlops,where mpg averaged 36.5 mpg,This year on hfp rims and the 205/45/16 Yokohamas avid h4s (a tire purportedly with low rolling resistance)I averaged 32.5.I also read all of the Great Mavens who postulate with scientific analysis how the maximum difference in no way could more than 1-2 mpg ,before I purchased.....Guess what Einstiens theres a fly in your ointment calculations.Heres what I say,Theres a set of Hfp rims and h4s tires in the classified section with 5k on them for 500$......

 

There are a number of things that could have led to your drop in fuel economy. It could be driving style, traffic, how the car is running and even the tread depth of the tire. A worn tire would rack up miles faster because of more revolutions per mile. A brand new full tread depth tire will have less revolutions per mile so it racks up miles slower. Unless you did this test head to head and back to back you really can't make a fair comparison.

 

I agree that there are many factors that contibute to mpgs last year in early summer with different loads on different roads at different speeds I averaged 42mpg on a weekend trip.The two trips (mentioned in the previous post)cross country are on Identical roads at identical speeds,at the same time of year/road conditions.My car is running fine I drive fairly consistent at the speed limit with cruise control.Wider low profile tires have several different characteristics than the stocks in question.They have the same size patch to the road but that patch is wider the sidewall flexes less,this contributes to a noticeable difference in the way the car drives,handles corners and curves,in addition the car is noticeably slower in takeoff from a stop.In addition the extra weight of the hfp rims (2lbs)and the lower tire pressure honda recommends (33-30 ).I have noticed more than a few times on this board that other hfp owners Have opted to sell there tires and rims after a short period of ownership.I am inclined to join them.I am not a Dr. of Engineering,but I offer my own real life experience for others on the board to use as they will.Maybe others who drive 16" rims can contribute different data,thats great.My conclusion for what its worth is That Honda designed the sport rims in weight and shape and matched it to the stock dunlop to maximize Mpgs.

 

As to tread depth a 205/45/16 is already slightly smaller in circumference (road rolling distance) than a stock 195/15.I replaced them not because they showed significant wear,simply because I thought to improve looks and handling.