Replace 235-50-R18 with 225-50-R18

As long as you replace all 4 with that size you'll be ok. The are just a hair smaller

rule is 1 size up or down>ok 235/50-18 225/50-18 Difference Diameter inches (mm) 27.25 (692.2) 26.86 (682.2) -0.39 (-10) -1.4% Width inches (mm) 9.25 (235) 8.86 (225) -0.39 (-10) -4.3% Circum. inches (mm) 85.61 (2174.61) 84.38 (2143.19) -1.24 (-31.42) -1.4% Sidewall Height inches (mm) 4.63 (117.5) 4.43 (112.5) -0.2 (-5) -4.3% Revolutions per mile (km) 740.06 (459.85) 750.91 (466.59) 10.85 (6.74) 1.5% Forum embed code: Speedometer Difference Speedo Reading Actual Speed 20 mph (32.19 km/h) 19.71 mph (31.72 km/h) 25 mph (40.23 km/h) 24.64 mph (39.65 km/h) 30 mph (48.28 km/h) 29.57 mph (47.58 km/h) 35 mph (56.33 km/h) 34.49 mph (55.51 km/h) 40 mph (64.37 km/h) 39.42 mph (63.44 km/h) 45 mph (72.42 km/h) 44.35 mph (71.37 km/h) 50 mph (80.47 km/h) 49.28 mph (79.3 km/h) 55 mph (88.51 km/h) 54.21 mph (87.24 km/h) 60 mph (96.56 km/h) 59.13 mph (95.17 km/h) 65 mph (104.61 km/h) 64.06 mph (103.1 km/h) so,whats for lunch ?

.39 inch that hair is.. andrew hey,i had nothing better to do but i learned something,.,. also his gas mileage is going to do down just a scoooach..

Just a heads up but I posted this for a friend. He is under the impression that his salesman at the Chevy dealership is in the know and when he told him in a conversation that he was going down a size in his tires the salesman got very serious and explained to him that the downsize would result in a transmission failure which of course is plain B/S. His mechanic of course disagreed with the salesman but of course he believed the know nothing salesman. The job is done and as posted the only affect is a minimal speedometer affect but the transmission does not care if it shifts at 24 MPH or 22MPH. Of course the installation of mismatched tires on the front will take the trans out.

Having different ones on the front won't hurt the trans either. Just messes up any abs and traction control.