Hi everyone just like to ask about my new rims I just bought. I have a 2007 Ford Falcon BF XT
with standard Tyres Dunlop 215 60 R16. I have just bought CSA Speedster 17'' Rims with Maxxis MA-Z4S 235 45 R17 when I drove out the tyre shop my car feels alot slower when taking off, and is it because the tyre are heavy or something can someone explain as I am new to understanding how rims work.
With the XR6 they are standard right! with these size Rims and Tyres, how different is it to the XT models when I look at engine spec they are about the same, do I need to get the speedo Reset with Ford Service or somehow get more power by modding with engine upgrades

new rims/tires shouldn't make it slower at all. did the tire shop take it for a test drive/hoon??

Went back to bob Jane Tyre shop and I explained what was going on they said because they are new tyres and wider it would have more grip and thread is full I said hmm ok so been that the speedo is off by a few digits would ford fix this problem by changing the Cars computers ECU DATA has anybody done this and how much would they charge

I went from factory 16's to 18's and notice there slight delay in take off ...

The b series have the speed sensors on the wheel hubs, so going up only one inch wont make your speedo go out. i went from 17 inch to 19 in my xr and my speedo is spot on..


You will notice your take off being slower due to the size upgrade. There is more wheel to turn now.. You will eventually get use to it.

Basically as LUMO said.... A taller profile tyre is much better for
take off and getting power down to the road. As an analogy, think about
the rear tyres on drag cars.... nobody is running shiny 20's and wafer
thin tyres there !!