Review on SuperSprings SSR-206-54: SumoSprings Yellow Rear for Chevy Express 4500 & GMC Savana 4500 - Review & Buying Guide by Mark Loredo

There are many opinions on these helper springs so I'll add my two cents. I added these and matching front bumpers to my 2018 Coachmen 27QB with a Chevy 4500 chassis and they made a world of difference. They don't dampen the ride, but they significantly reduce side-to-side sway when you're on the road. I also added a SafeTStop steering stabilizer and the ride is much more relaxed as a result. The constant readjustment of the steering is no longer necessary, driving becomes significantly less tiring. Didn't do any long drives until fall so can't say how this will help with semi trailer passing but I expect based on other reviews it will be much better than the standard.