Vehicle Dynamics and Rollover Stability

After 42 years of engineering services Dr. Renfroe, who founded the company, now known as Ei Consultants, has decided to take a sabbatical for two years.  He was called to serve a mission in Africa. This is something that he and his wife have looked forward to for some time. We are excited for the adventure he and his wife have ahead of them. We will miss his lively personality and insight he brings to investigations. We also look forward to his return in March 2018.

We have qualified and experienced engineers on staff who have worked closely with Dr. Renfroe for many years.  Please call our office and our staff will connect you with an engineer who can assist you with vehicle dynamics and rollover stability case related issues.


Paul T. Semones, P.E., M.S.M.E., is a licsenced Professional Engineer and an experienced investigator of crashes that occur as a result of tire failures. Mr. Semones has personally investigated over 200 documented crashes caused by various tire failure modes. These investigations have included numerous cases of solid rear axle tramp during a tire tread separation. He has personally directed several test programs involving tire disablement on solid rear axle vehicles, and studied the issues extensively.

Mr. Semones presenten an hour-long seminar at the ARC-CSI Crash Conference, teaching accident reconstructionists how to recognize and document the evidence from tread separation crashes that involve axle tramp. Police officers and reconstructionists from around the world learned why some accidents may not be attributable to "driver error," or "unsafe turning movement," or "failure to maintain lane."

The following videos demonstrate the testing of roll propensity of a vehicle and the handling test of a vehicle with a delaminating tire.

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About Us

Ei Consultants, LLC was organized in 1984 by Dr. David Renfroe. The company is now owned by Stanley Andrews.

Ei Consultants, LLC provides engineering consulting and research services. Our engineers have expertise in the areas of accident reconstruction, fire origin and cause, and industrial accidents and machinery.

We also contract with engineers with experience in the fields of tire failure and design, ATV and UTV Testing and compliance, and vehicle dynamics.

Contact Us

2575 E. Heritage Parkway
P.O. Box 610
Farmington, Arkansas 72730

479-846-8002 Fax


Office Hours: 8a.m. - 4:30p.m., M-Th


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