Trying to find suspension specs for the 2018 Prius Four Touring

I had been wondering that too, and haven't found that there's any mechanical difference for the Touring trim line. Looking at the attached 2018 e-brochure, nothing is described, and the only differences in the Touring specs is the "track," which would be due to the 17" wheels; there are different front lights and rear bumper. The Touring trim was eliminated in 2019, when the Prius lines went to common Toyota L-eco, LE, XLE and Limited - - there's no SE or Sport line.

 

The main feature for Touring grades is the 17-inch wheels. Besides the difference in track kindly mentioned by @pjksr02, New Car Features (more info) says the outside front turning diameter is larger (10.4 m, rather than 10.2 m), and the steering overall ratio is greater (13.6, rather than 13.4).

The Electronic Parts Catalog shows two versions of the steering gear assemblies and shock absorbers, but the same stabilizer bars and coil springs. The spring length is different only for “Rough Road Area Specification” models, which have 20 mm higher ground clearance and don’t seem to be sold in the U.S. mainland.

For 2019 and later models, New Car Features discloses a more substantial difference in the shock absorbers. Those on Touring grades use a “multi-leaf type linear control valve,” but those on other grades use a “high response type piston valve,” in both cases for “ride comfort and controllability.”

Yes, they do—or at least, they made the ones on the car that was torn down by the Hiroshima Industrial Promotion Organization.

 

I'm very interested to find out how to order the "Rough Road Area Specification" suspension with a higher ground clearance that you were mentioning. I have a 2019 Prius LE and am about to order the lift spacers from either Prius Offroad or eBay (depending on if there is any significant difference), and would also like to change the shocks and struts as well. If there is an option of higher clearance that would be even better!

 

As far as I know, this is a specification set by Toyota based on the destination region, and it’s not offered as an option, before or after sale, on cars built for the mainland U.S. market.

If you wanted to modify an existing car, a reasonable starting point would be Toyota’s Electronic Parts Catalog, to identify the service parts that differ on “ROUGH ROAD AREA SPEC” vehicles. I’m not sure I’d recommend this, however; the resulting vehicle may not have been evaluated to U.S. safety standards, and there could be other unexpected complications.