Has anyone ever experimented with a slightly larger diameter wheelset to close the gap between the fenders and tires? So instead of lowering the car 2 inches to meet the tires (always results in a harsher ride), could you increase the tire diameter to meet the fenders and maybe only lower it 1 inch to maintain some ride comfort.

Obviously some adjustment needs to be made to correct the speedo readings, but on most vehicles this ratio can be reprogrammed. You would also gain some slightly better gas mileage and higher top speed.

Thanks.

 

bigger wheels/tires usually == heavier, so you'll lose quite a bit of torque there. rotational inertia = mass x radius^2. that means that increase in diameter will increase your tire's inertia pretty significantly.

 

no way to reprogram our ecu's to account for bigger rims..
also, i had 19's up from the stock 15's and there was still quite abit of gap.. best thing is to get a set of springs / coilovers and get shocks with matched needle valves for your spring set up, to be as close to a stock ride as possible

 

Snap-on makes a diagnostic scan tool used to read error, cel, and other codes thrown by any car including our cars and you can in fact change wheel and tire sizes to adjust mph so you dont throw any codes or have any abs traction problems. What do you think people with 28" rims on there GMC Denali's do? The tool is expensive and has to be updated to new models every 2-3 years, check it out.

 

The easiest approach is to keep the outside diameter the same. I usually go +2 from OEM so my error is quite small, if done exactly it shouldn't be off at all, what you gain in rim you give up in sidewall.

 

There are a lot of issues that popup when you do this. It does sound simple though. A lot of people ask us questions like this. The Lobster is correct you won't get better gas mileage due to the extra weight, you'll also wear through bakes faster and your probably have some rubbing issues at full lock out, recalibtation of the speedo, like you mentioned, will also need to be done.

A better solution is the drop, A cheap kit will run you about $150.00 and a nice kit, like Eibach, will run in the low $200 dollar range. Installation is usually pretty cheap too. I had my last car done for $100.00 For just over $300 you'll have a more responisve suspention and the look you want.

 

hwybox - are you sure the snapon scanner will in fact change our spedo readings? i know it will work on domestics, but when speaking with toyota / scion, and snapon, they could not guarentee this would work on our ecu's. trust me i have been looking for an option to recalibrate my spedo, looked at scanners, in car diagnostic software, i have been looking believe me... i am trying to hack the ecu now and see if i can figure a way to reprogram the tire size... yay pick a part ecu - $50.....
if you have used the snapon tool and changed the tire size on a scion, let me know and i'll buy one, but if you "think" it will work on our ecu and have not actually tested it then i'll have to go with what the toyota techs told me, that its not possible... for that matter, if anyone has had sucess using the snapon tool to reprogram for tire size on a scion, let me know because it would be a much easier fix and believe me there are much funner things to hack into then an ecu from a junked xb,,. i dont mind buying the unit, i have a decent obd2 scanner, but it will not reprogram for wheel size.. i have heard the snapon one is better.

 

you can install bigger diameter wheelset just to close the gap BUT there will be major issues with rubbing

 

Wow, great information here so I'm subscribing to this thread.

Personally, I'm running 215/55/17 tires on my car which are a little bigger than stock. The front fills in the gap nicely, but still leaves a hefty gap in the rear. My mileage is thrown off, but at least I don't get any error messages thrown my way.

 

My dads shop has a couple different brands of scaners Snap-On, MAC, all the auto-tecs buy their own I think my dads was around $2500. When my 06 xB had some codes CEL, VSC, ABS the reader was only updated to 2004 vehicles so we looked it up as a 03 or 04 Echo and cleared the codes, that ended up being allignment was off and a bad gas cap seal. Then I took it to the dealership under warrenty got a new cap and paid for a $90 allignment (my dads shop does not do them).