This is one of those questions that does not have a tidy yes or no answer. The "five star rating" has to do with the ability of a vehicle to pass a very specific impact test. The US federal government has two main impact test standards: frontal impact and side impact. The insurance institute uses an offset frontal impact test and a backup test. The problem with test standards is that the manufacturers can design a car to perform very well on a test, but it may not indicate their performance in the real world. Very few accidents involve cars that drive into an impact barrier along a perpendicular path at a precise speed. Ditto for the side impact test. The offset front impact is more realistic than the straight frontal impact test, but still has limitations. One of these limitations is that the offset impact test is biased towards the insurance repair industry and reflects the costs associated with auto repair, as well as the safety of the vehicle. The rear bumper test, for example, is for the purposes of the insurance industry and has little to do with safety. What happens if a car hits a different vehicle at a slightly different speed, higher or lower? Or at a slightly different angle? Or if there are substantial differences in ride height between the vehicles?[*1] Or a large difference in vehicle weights? There are numerous such variations. The standardized tests do give you a relative assessment of occupant safety, in that a vehicle with a one-, two-, or three-star rating is inferior to one with a five-star rating. The difference between a four- and a five-star rating may be insignificant, and could be no more than one point to either side of the dividing line. You must use your own judgement when small differences are involved. Vehicle rollover testing is another key ingredient and NHTSA has been subjected to some unsubstantiated questioning over the test methodologies. However, these tests remain a very good indication of the rollover risk in a vehicle. While a five-star rating may differ from a four-star rating by a couple of points, it is substantially better than a three- or two-star rating. In general, low and wide cars perform extremely well on rollover tests. Having performed rollover testing on motor vehicles myself, I can vouch for the validity of the adopted test methods and the rationale behind them. (Rolling over a loaded transport truck can be a heart-stopping experience the first time you do it.) So, is the SUV with five-star impact rating safer than a smaller car with the same rating? Not according to the test, but perhaps so in the real world. Many feel a security in SUVs because they ride higher and weigh more. This does impart a certain amount of additional safety. On the other hand, some SUVs and pickup trucks are considered to be very dangerous to other vehicles on the road, because their bumpers are located too high off the ground and they have a high ride height. This increases the probability that they will climb over a lower car during an accident. They may protect the occupants of the SUV slightly better, but they kill and injure passengers in other vehicles who might otherwise have survived. Given the inherent tendency of an SUV to roll over more easily than a conventional car [*2] and the lack of driver skills most SUV owners demonstrate in handling large, heavy vehicles, they pose as serious or, possibly, a more serious risk to their drivers and passengers. A tall, heavy vehicle requires a different set of driving skills than a low, light car, especially in poor road conditions. My personal impression is that I see more SUVs and pickup trucks in the ditch after ice storms than any other type of car, because their drivers lack the experience to control them properly. When was the last time you heard of a Honda Civic rolling over in normal traffic? And vehicles in rollover accidents kill a far higher percentage of their occupants than they do in other accidents. A five-star rating is only part of the story. [*1] A former co-worker of mine was involved in a frontal impact with a bus. The car certainly had a very safety good rating at the time. However, the differences in the ride height and momentum of the two vehicles caused the bus to climb up and over the passenger compartment of the car, killing the occupant instantly. [*2] Tall vehicles have a higher vertical centre of gravity, which is directed related to their ability to resist rollover. The higher the vertical CG is relative to the vehicle's track width, the more likely the vehicle is to roll over. This is aggravated by the use of roof racks on cars, which substantially changes their rollover performance. ------------------------------------------------------------ Re: "are more trucks active in snow" Not in my experience. People usually drive the same vehicles throughout the year. There are no more trucks and SUVs on the roads in the winter than there are during summer, once we exclude road maintenance vehicles. I am referring in this example to vehicles that I have observed having difficulty under poor road conditions, as well as a few articles and papers that I have read. Much of the traffic I see is commuter trafiic, with most of it on semi-rural secondary and tertiary roads until recently. Part of the problem stems from the driver's over-confidence in the security of the vehicle and part from a lack of experience in driving heavy vehicles. Drivers particularly have problems in bends or corners, where slippery roads, inadequate tires, and vehicle interia combine in unfortunate ways. (Any all-season tire more than a year or two old is inadequate in winter, except on well-maintained city streets.)

Have your ever watched the vehicle "big foot" drive over smaller, parked automobiles? to me, this is a classic example when comparing an suv and a small automobile. stars do not make the difference, its the size. common sense tells you anything thats big, is going to dominate over something thats smaller. i have worked many traffic crashes involving suv's vs. small auto. the suv's always sustain less damage, than the smaller vehicle. when you compare height and weight of the suv's against the height and weight of a small auto, its like a dragon vs. a deer. no contest. suv's are higher off the ground. this sometimes gives the driver a false sense of security. 5 stars 10 stars, actually make no difference in greatest property damage and personal injury in a crash. its the shear size of the suvs that dominates.

Crash testing does two things (besides wreck lots of new cars) the first is to determine the survivability of the persons in the motor vehicle within what is called the safety cell. The second is to determine the dissipation of energy that is created when one solid object comes in contact with another. There are two basic problems with the U.S. crash testing system. The first is that the speed that is set is too low. The other is that we don't hit other vehicles at perfect right angles. My own personally view is that SUV's are not safe, even with a high rating. US testing does not take into consideration that the SUV will most likely roll over even at a low speed as it dissipates energy. The energy will then work against the vehicle because if its weight and height. The standard sedan has a greater chance of surviving an accident because it has a lower centre of gavity however, in saying that, the sedan is smaller and lighter. Hitting a larger object then compromises the safety features build into the car. U.K. testing is fair better as it takes far more possibilities into consideration, including large cars hitting small cars. and cars colliding at any angle. As car making continues, cars will become safer. There are a number of problems we still need to address. There are just too many old cars on the roads today. Driver training is simply just not good enough. The road and highway system is old, outdated and in many cases a contributing factor in car accidents. The public has accepted that a certain number of deaths on the roads are an acceptical. I'm heading off the topic, sorry. Yes five stars are good. I just hope I hit another car the same size with the same number of stars.

I am an a-level physics student and we have done work on this. let me give u my perspective. supposing they both r going at the same speed and towards each other heading for a collision...both have 5 star safety rating but which one do you think will be damaged more..the tiny car (of mass say 1 tonne) or the suv (of mass say 1.5 tonnes)...logic tells u it will be the tiny car...why because its bigger and heavier...we say it has more momentum than the car which leads us to the equation p=mv....the mass x velocity (which is same on both cars) and only mass is different...its like an elephant charging at you..not very fast but very heavy...imagine what it could do if it could run as fast as a cheetah. you could also think of this in terms of force..which has the greater force...the equation f=ma tells us mass x accelaration which if constant meaning zero tells us the suv has more force than the car hence inflicting more damage on the car or if they are both accelarating at say 10m/s still tells us that the suv will inflict greater damage on the car...both these equations takes into account mass...so to answer your question i think the suv will be safer. the car is still safe if it crashes with another car but with an suv...no chance....but what if an suv crashes with an 18 wheeler..ill let u figure that one out...i may be wrong and please tell me if i am wrong or right..after all im only a student in my first year.

I don,t believe these tests answer your your question, I like to know which car is safer and crash tests or real world collisions do not offer data that in accurate. regardless of how accurate the data, if you gather data from part of the bigger picture, you never have a good statistics. Crashes are part of a automobiles safety record, possibly not a major one at that. I would like to see data about cars that can avoid accidents due to their design and handling. After-all, It is walking away from your car at the end of the day that counts, whether you crashed it or not. I would like to see data about each car or least each class, that shows the percent of deaths and bad injuries. For example if data showed a SUV with a 5 star rating has 10 deaths per 1000 owners a year vs. a compact passenger car rated 1 star but 5 deaths per 1000 owners, (throw in the number of hours and miles driven for better stats) I would say the later is safer. That does not change the fact that in a crash, you are safer in the five star SUV. If I new nothing about anything and was offered to be transported in something. I would like to know chances of walking out of it alive. I don,t need the details about how each vehicle has different safety features for specific areas. I don,t want to ride the one that has a high percent of death and injuries. I don,t care if it can smash all the other one in a crash. I guess the star rating is the next best thing if overall safety data is not gathered.

In a side impact with a SUV (if you are in the small car)that is not equipped with side airbags, your head can actually break the window and hit the hood of the larger vehicle. This can cause severe brain damage. However SUVs do roll more often, so you would be better in situations where you had to avoid something. If you need to buy a small car for gas mileage or price, if you get the side airbags you should fair about the same as if you got the SUV. Of course this is assuming that you are talking about 5 star ratings all around, not just one category. Note though, that the crash tests are very specific, and do not measure certain things like rear end collisions.