Ok I was running nitto nt05r's 275/40/17's. I switched too 26/11.5/17 Mickey Thompson et streets on the back. I know it dropped my r's almost 300 at 60. The car doesn't accelerate as fast either. How much slower is my car if both tires were dead hooking?Also not sure what my tachometer was reading when I crossed the line I just know I lost quite a bit of acceleration. Would this mean the smallest tire that hooks the best would be better as long as you weren't revving past your power?

 

An M/T ET Street Radial in that size is 26.0". The 275/40-17 is 25.7". The difference is only about 1%..... I doubt you would even notice it. To see the RPM drop 300 at 60 MPH (In 4th gear?????) would take a 30" tire.

Something is screwed up.

 

Then im sadly mistaken on the size. My speedometer is off severely due too the 4.10 gears and not changing the speedometer gear in the tailshaft. The nitto's would read 80 mph when I was doing 60. The et streets im running read 72 @61. The nitto's had zero fitment issues. I had too pin part of the fender wall back just too fit the et streets. When I step outside ill look at the tire size. Would width slow me down at all?

 

A wide tire adds weight, and takes more HP to accelerate it. But I doubt you would feel that either.

Are the tires ET Street, or ET Street Radial? The ET Street 26x11.5-17 is 26.5" diameter. The ET Street Radial 26x11.5-17 is 26.0" diameter.

 

They are et street's not radial.

 

Still doesn't account for the huge drop in RPM.