1st Nov 2011, 13:44

Would like to know what happens when your diagnostic scanner malfunctions, or your automobile's CPU decides to go haywire with a solar flare, or your coil on plug decides to play happy families?

1st Nov 2011, 14:11

Anecdotal stories won't make up for engineering facts. Sorry. If we're going to use that sort of logic, then I can just as easily use my own story - and yes, this is a REAL story. My Mom has a 2007 Honda CR-V, which even though it's a small SUV, is built on a unibody frame. Her car was rear-ended by a full sized Buick. Her car was basically un-harmed and suffered from a dented plastic bumper cover, which was later removed using a heat gun. The Buick on the other hand suffered from a lot of frontal damage. So I could just as easily go - ah-ha! See? Her car was unscathed and the other one was damaged beyond repair!

But that's not proving anything. Talk "Hype" all day long, but I'm not sure why that word would be used when it's not hype, but rather scientific fact that a more carefully engineered unibody frame vehicle can be and is often even safer than a body-on-frame vehicle.

As mentioned before, this isn't an argument because there is no argument here. Simple.

1st Nov 2011, 16:48

Depending on how old that Buick was, it is quite unlikely that it was a body on frame construction. The last Buick to have that type of construction was a 1996 Roadmaster. For the most part Buicks have been unibody since the mid-80's.

1st Nov 2011, 17:00

I never had an issue working on either or, but after being in the field for many years, I can say that older cars are easier and far more fun to work on, and you don't need expensive diagnostic tools and scanners to work on them, because cars from 20 years ago and before that, barely have any sensors at all.

1st Nov 2011, 17:03

And the full-size Buick that hit your mom's car was a UNIBODY Buick LeSabre. You have mentioned this story before, therefore it was unibody vs. unibody, so there really is no comparison.

1st Nov 2011, 18:51

In rear-enders, the car is front is seldom damaged to the extent that the car in the back is. Try hitting a CRV head-on with a Buick, and see which one drives away!!

2nd Nov 2011, 11:28

Dunno. Probably the same thing if the coil for your cap, rotor and points system burns out, or your cap and rotor becomes burnt-out, or the carb floats sink, or the alternator/generator fails, or the fuel pumps stops working or whatnot.

I've yet to hear of solar flares causing issues on a car computer - which is probably due to the fact that car computers are solid-state and don't use hard drives. Either way, what exactly was the point again?

2nd Nov 2011, 13:43

Well put it this way, if the engine is missing on a car that's not so dependent on an ECU, yes you check plugs, points, rotor arm, and every other thing to do with the ignition system, and you will find the problem, and if not, you try fuel system and so on.

If the charging system is not charging, you can easily check it.

All of these things can be checked without having to have marque or manufacturer specific software.

Now it is a fact that that more electronics are on a car, the more complicated it gets e.g. some cars with CAN-bus or multiplex wiring, where an actual circuit will only switch on when it gets the correct frequency. So when a unit fails in a circuit, it may not be it, it might be the receiver in that unit that is not processing properly. So go to your local dealer, they plug in diagnostic equipment, and you are at their mercy as to be robbed or told the truth. Something you have to do if you drive a car heavily laden with electronics.

2nd Nov 2011, 16:13

To 31st Oct 2011, 16:51:

But what if the computer which produces those codes you rely upon goes bad? This is quite common. It is just another excessively complex part to go wrong.

2nd Nov 2011, 19:31

Once again, this is a non-argument. Those making the argument that a body on frame is safer than a unibody frame are wrong on all counts. Sorry, but science and engineering have a way of being correct in these matters. Secondly - again - if you don't know how to work on modern cars, don't blame the car's technology if you fail to understand how it works or don't know how to diagnose them. If you know how to work on modern cars, they're a cinch.

3rd Nov 2011, 09:25

I agree with you, and this is where to get the scoop on safety: http://www.nhtsa.gov/

3rd Nov 2011, 10:47

I have never had a computer in a car go bad. Ever. I've known exactly one person who had this happen, and the car had been in an accident. Car computers are not like home computers at all. They are more simple and solid-state with no moving parts. I could just as easily ask what would happen if the condenser, points, fuel pump, or any number of the myriads of components in a old car went bad.

But the other thing is that you have to realize what computers in cars do. They monitor what's going on with the engine and drivetrain. An older car doesn't have this, so if something is going wrong and it's not immediately detectable by the owner, it can go unnoticeable until the damage is done. On newer cars, you are informed of this right away, hence potentially avoiding costly repairs.

3rd Nov 2011, 14:13

Fellows, if artifice always triumphed over mass, then hitting a tree or a boulder would be no problem. The assertion that this debate is 'no argument' is offensive, and I suspect a sign of precisely the weakness of your argument. None of us nostalgists deny that clever technology can do some good, but the point is that it can never fully overcome the lack of mass in modern cars.

4th Nov 2011, 00:56

They are a cinch to work on. By that remark, I take it that you are a qualified master technician who specialises in modern automotive electronics.

4th Nov 2011, 12:32

This discussion is utterly useless. Believe what you want to believe. Just be aware that things change, technology improves, and so on. I'll summarize this down to the extreme basics and then I'll leave it at that, because clearly again - this is a sort of meaningless debate, because everyone already made up their minds anyway.

With a body on frame design, the body itself is not as integral of a structural component of the vehicle, since it basically sits on top of a frame. With a unibody structure, the entire vehicle is itself the frame. In an accident, the most critical thing is what happens with the transfer of energy, and how this affects the driver. In a BOF vehicle, often times the impact runs down the frame. With a unibody structure, that impact is more evenly spread and the energy is absorbed more evenly.

Secondly, why do you suppose all modern sports cars use a unibody structure? It's because a unibody frame tends to be more rigid, which means the car handles better.

Now - that isn't to say a BOF vehicle isn't safe. But if the argument is that they're safer than a unibody frame, then that point can be argued because to assume that all BOF vehicles will suffer less damage or keep its occupants safer is not really accurate, because there are too many factors depending on the design and age of the vehicles in question. BOF vehicles have their place: They are great for trucks and commercial vehicles.