Most drivers slow down to nothing before crossing over these plates. I prefer to take them at the speed limit. Is that worse for my tires? Does it make that much of a difference to slow down?
Yes, it does make a difference. Your tires, suspension and steering gear take a pounding and now they hate you.
Oldmotorist
But isn’t my car meant to handle this kind of thing? It’s a 2 or 3 inch plate. A pot hole is worse than that.
You should slow down for potholes, too. Steel plates have square edges, the type that could damage a tire if taken at high speed, even damage a wheel if you have low-profile tires. Slow down.
You are subjecting your suspension components and tires to an impact that will hasten their demise. Yes, it makes a difference.
Has anyone else driven over the floating bridge that crosses Lake Washington in the Seattle area? If I remember correctly either the entire bridge is made of multiple steel plates for the road surface or jusr sections. Well whatever is the case these steel sections give a very odd road feel, hard not to want to slow down on them.
“I prefer to take them at the speed limit.” Okay Mom…But the speed limit signs were put up before the steel plates were put down…Radial tires, especially the side-walls, are easily ripped open by those sharp-edged plates…It’s your car and it’s your money…
It’s all in the speed and very difficult to generalize. Regardless, tires/rims are more prone to damage if under inflated.
It makes a difference. It makes a difference in the life of the car and tires to just slow down everywhere, even with no plates or potholes around.
Your actual question “Does it make that much of a difference” is more difficult to answer. Personally, most of the time it doesn’t for me. I even cross railroad tracks (the better ones) at full speed without issue. If it reduces the life of parts of my car, it has been too minor of an amount for me to notice.
I figure (right or wrong) if it is jarring enough to bother me, then it is jarring enough to cause trouble for my car. If it doesn’t bother me, it probably isn’t hurting my car too much either.
3" steel plate no way I’d hat that at what ever the speed limit is. Why is your area using such thick plates. The thickest I see around here is maybe 1.25".
Are the plates in question the slats that cover expansion joints in the cement roadway on bridges? They appear to be about .25 inches thick and 3 inches in width and would not appear to be a problem at any legal speed. But a 4 inch jump would likely do a great deal of damage to most automotive tires at even 30 mph.
Most the plates I have seen are 1". Sure there is the same fear as walking over a vent grate in the sidewalk in the city, but a 1" bump in the road, makes it better than the bumps in a lot of roads I travel. Now worries in my mind.
No. Why would it be made to handle a 3 inch vertical surface? It’s a minivan, not a Hummer. Slow down - it’s only a few seconds out of your day 
I think she’s talking about those metal plates they sometimes put down in construction zones to get you over the big hole they just blasted in the road.
Depends completely on how they are set. I err on the side of caution. Honda suspensions are beyond expensive to repair.
In the end it depends on how long you keep your vehicle. If only 5 years and trade off drive on. If you plan on the long term you may find some nasty rattles and expensive suspension repairs.