Perceived braking irregularity might be a road surface issue

Brad, I have a problem withmy 2013 Lexus IS 250c that has been going on almost from the time I began leasing it. When I brake for a stop sign or light sometimes (but not always) the front wheels will turn abruptly to the left (and even occasionally to the right) as I come to a stop. The steering wheel will make about a quarter turn to the left. Knowing this I can prevent it by grabbing hold of the wheel which I believe I shouldn’t have to do. I have taken it back to the dealership at least three times, and they assureme that the car meets the alignment standards and there is nothing wrong with it. They attribute this to the lowprofile tires, “crowning” in the roads, etc. I find it hard to believe that Lexuswould design a car thatwould do this with tires designed for it and told them so. The car has bumper to bumper coverage (and lowmileage) and is a car Iwould consider buying at the end of the lease… but not with something that might be a problem downthe road. — Paul

Paul, I have a feeling your dealer folks may be correct. Pavement irregularities at stop signs and stop-lighted intersections are common, due to thousands of vehicles scrunching the asphalt when braking to a stop.

Here’s an idea: Find a parking lot with a really smooth surface and try a variety of stops— firm, gentle, straight, turning slightly— and see if you can duplicate the condition. If you can, theremay be a suspension or tire issue that hasn’t been properly diagnosed. If not, your somewhat wide/low profile tires are not happy with typical intersection pavement.

Next, I’d experiment with tire pressure, raising it a few pounds, but staying at or under the maximum inflation pressure listed on the tire, which could help. This seems to be a lengthy lease! If you’ll be replacing tires before returning the Lexus, try switching to a symmetrical tread tire or one recommended by your tire dealer. Perhaps you can negotiate an exchange policy in advance if you don’t care for the performance? My new fifth wheel trailer came with 10-ply tires made in China. According to many people in the RV forums, these are referred to as “China Bombs” and by running them I’m risking an expensive or dangerous failure when they pop. What is your opinion? It seems crazy to replace brand newtires. — Sal

What’s more important than where a tire is made is the tire load rating vs. your actual loaded weight, and how diligent you are at maintaining correct pressure at all times (a tire pressure monitoring system is a very good idea!). The tires that came onmyRVonly provided a 15 percent reserve between rated and actual load, and it’s logical to assume a tire’s load capacity diminishes with age. After checkingmy wheel rating, I upgraded from the 10-ply 80PSI tires to 14-ply 110PSI tires, adding about 2,000 pounds of load capacity— a much larger reserve. Upon mounting them I was amazed at the increased weight and sidewall thickness! It’s probably best not to mention brands. I researched variousRVforums and pored over specs, and went with the brand/model folks complained about least. And it turns out they’re made inChina!

Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, Calif. Readers may send him email at bradbergholdt@gmail.com; he cannot make personal replies.