Modifying an SUV to be the safest possible family vehicle

I received a very thought provoking letter from a reader in Miami, Florida asking about the safest possible family vehicle. Readers, what are your thoughts?

Dear Rob,
My name is Diego, and I stumbled on to your post about vehicle height precisely researching on vehicle safety. My wife is pregnant and two months away from giving birth. My baby girl is not even born yet and I'm already a very overprotective father! As soon as I found out she was pregnant I bought her a Chevrolet Equinox, IIHS top safety in the SUV department. The other day I was thinking and I figured that there are trucks and SUVs out there that are a lot
larger than my wife's SUV.

So with the intent on my future princess being extremely well protected from the ever-so-common-in-Miami car accidents I want to buy and modify the safest vehicle I can. I was thinking on the lines of buying a Ford Excursion for its very large size and mass, maybe lifting it a few inches but also widening its stance to prevent the rollover risk and then going on to have it fitted with the same solid steel front and rear bumpers seen in many off road and work vehicles, also have it fitted with any kind of extra support for the roof columns, internal door supports etc. After reading your post, I've also considered implementing large heavy duty brembo brakes for stopping power. So my questions to you are:
1) On equal terms will a vehicle with a greater mass be safer to passengers in the event of an accident?
2) What car, and what modifications would you recommend to me? I want to either buy or build the safest family vehicle out possible, money is not an issue at all, price of the vehicle or how much it costs to have a shop modify it is not a factor.

Thank you for your attention and I apologize if the email is longer than just a question, but I did want you to know what was on my mind so you could have a background to work on! Thanks again and have a great day! I’ll be awaiting your response!

Sincerely,  Diego

Hello Diego,
I certainly understand being overprotective! I’ll cover each of the points you raised. Keep in mind potential compromises as these topics are vetted. For overall size and rugged build, an SUV is the obvious choice. Also keep in mind it isn’t just accident survivability, but also accident avoidance by handling, braking, driver skill and decision making.

1. A vehicle with greater mass may be safer in an accident, especially against a lighter vehicle. However, drawbacks are potentially increased stopping distance and an adverse effect on emergency handling. Secondary to your points, fuel efficiency, brake and tire wear and if a larger vehicle, practical maneuverability; are all negatively effected.

While I could initially recommend a crew-cab heavy duty pick-up truck, braking distances are sub-par and emergency handling is very poor. The overly large size is restrictive for parking, service, etc. Finally, with a curb weight of 3 tons or more, I can’t even speculate on the cab roll-over protection the vehicle weight works against.

2. Regarding modifications, this can be a tricky proposition depending upon the vehicle. I always recommend opting for the sport package because performance oriented upgrades mean better handling, upgraded tires for better grip (handling and braking), and overall heavier duty components.

A tire and wheel upgrade package would likely be as effective as larger brakes for a well engineered vehicle. Larger brakes don’t necessarily mean a shorter stopping distance, but rather better repeated braking performance and less wear. A significant weight increase would also justify larger brakes. Evasive driving also justifies a larger brake package.

Raising a vehicle will have an adverse effect on handling, potentially braking and increase rollover risk. Widening the stance with spacers, assuming they can be found for an SUV can help minutely provided there is room without protruding past the fenders. You don’t want to overly stress components and void a warranty on a highly capable yet heavy SUV.

Structural reinforcements can have benefits, but have negatives too. A reduction of a crush zone increases the g-forces on occupants by reducing the deceleration time after impact. Cabin reinforcements can be very costly and roll bars must be heavily padded or cause greater injury than without. My suggestion would be to contact a vehicle modification company such as O’Gara since this is their specialty as well as for firearm resistance, another important consideration.

Some rare safety features that offer superior occupant protection are self-contained seat belt and seat assemblies. This is an expensive engineering feat. A five-point racing harness is an excellent safety modification but requires expert incorporation and replacing existing seats. Another feature is an airbag incorporated into the seatbelt. This was recently observed in the 2014 Ford Explorer Sport, an impressive SUV.

A capable, safe and performance oriented SUV is my recommendation. There are good SUVs and there are great SUVs. I would choose from the highest performance versions of the BMW X5, Porsche Cayenne, Mercedes M, G or GL class or Land Rover because of their fantastic driving dynamics for an SUV and heavy duty construction. If you wish to modify beyond what is offered, I recommend contacting O’Gara and Canepa Design since they can offer expert consulting based on their modification experience and enhance whatever you choose.

Finally, the most important aspect of occupant safety is the driver. I highly recommend performance and tactical or emergency situation driver training for your wife and yourself. All the structural reinforcements and accident avoidance capacity are null and void if the driver makes poor choices, panics and hesitates. Extreme braking, acceleration, slalom maneuvers, obstacle avoidance, J-turns, etc. should all be in your ability with confidence. This is the most important part of occupant safety.

Good luck and keep me posted on your choice and send pictures!