So dad says no lift allowed because of the increased danger in rollover, but Im not buying it because of how minimal 3 inches up is, especially when i put on spidertrax and widen tires from 265s up to 285s... Anyone have any knowledge of exactly how much a 3 inch lift really does to the geometry of the car???

3" may not sound like a lot; however stock ground clearance is ~8" at the lowest point. A 3" lift + tires is nearly a 40% or more increase in height. Just something to consider.

HOWEVER, depending on the lift that you go with, some coil-overs will increase stock performance by decreasing body roll and brake dive.

ClockWork,
Let's try to make this a thread so he can show his Dad that it's not really that big of a deal so he can get it a lift..

In reality as long as you get some wider tires along with spidertrax, then you'll be fine as the wider it is, the harder it is to flip.

tell him the upgrade in suspension would probably decrease the probability of a roll over. stock vs after market kind of a no brainer really. as far as the height 3 inches wouldnt change your center of gravity which is the main thing when looking at rollovers. id say no more than a degree or two when looking at the angle at which the vehicle can lean in one direction safely before rolling.

Fixed.

So how exactly do car companies come up with their rollover ratings?? If i can prove all this with math and stuf, think Thatd seal my case:-)

Vehicle Dynamic Rollover Propensity | National Highway Traffic Safety Administration (NHTSA)

hahaha wish there was just an easy equation, but no, cuz this is America and there's 9 steps to every process...

When I went to the Icon coilovers- my 4runner handled better than it did when it was lower. Stiffer springs and better dampening. It's still an SUV, don't drive it hard.

Your 4runner has stability control, so it should keep you pretty safe!

I did a 2.5" lift on my old truck (a 3rd gen) and my parents, at the time, were skeptical on my ability to install it and that it would be worth the time and money. I actually got complimented from them once it was done for not only the look but also my ability to put it on.
That was years ago, however. But I'd say with aftermarket stuff, you wouldn't have any issues. Unless of course he has valid reasoning because you happen to be a reckless driver, ha. (Not saying that you are or where you live, just a light joke).
I don't know the formulas, although I took years of Physics, but I do know that you'd be any worse off if you got a lift on the truck. I do agree that it raises your center of gravity, but how many accidents occur with lifted trucks compared to stock trucks? Is the lift truly a factor in an accident? Doubtful, yet debatable.

He should be concerned. He is already trusting a kid with a $20,000+ car. Aside from the increased possibility of roll over, teenagers are not (historically) the most responsible drivers. There is also the concern that a lift will give you the encouragement to take the car to places that increase the opportunity for damage (off-road, mud, rocks, etc) Not only does this increase the possibility of getting stuck/stranded but increases the repair bill exponentially. If you're not going to be taking the car to those types of places then why do you need a lift at all.
Sorry to have to play devil's advocate, but you should probably hear the logical arguments that your dad is thinking about when it comes to protecting his kid and investment. We all know what it is like to want, but the things you buy when you achieve the financial independence and provide them for yourself will mean more when you can make your own decisions. If he has to pay for the lift, spidertracks new tires and installation for all of it then he may be just as concerned about that bill as the potential repair bill and your safety. Out of curiosity, what do you need a lift for anyway... EDIT: Because it would be cool is not going to get you anywhere in this argument...

Go ahead flame away, it's nothing new. Logic is almost always met with an irrational, emotional rebuttal.

When you have a 4Runner adding things like lifts, high performance exhaust systems, upgraded lighting etc. because they are cool seems pretty normal to me.

Dusty Driftwood,
How old are you man? I understand that you wanna be a stickler in this whole thing, but the kid asked what could I use to convince my Dad to let me do it..Not hey let's hear why my Dad is right! He wants to do it because it's cool. Let him have that and if his Dad calls you and asks you why it's bad, then you can tell him what you posted. We're trying to use this thread as a way to talk his Dad into letting him lift it.

I had the same argument myself. My tires currently have 15K left on em. My Mom told me the only way I could do it is if I paid for this set, and the kit. Try to assure him that the only thing you're changing are the shocks (which need to be replaced anyway), tires, and your coils. So essentially the only thing you're paying for that you don't need are the coils. The car will ride better, look better, and you'll love it more. Run that by him. Hopefully it helps!

haha dang, ran me over with that one! Not to ramble and with no disrespect, I feel like you assume too much. You should know that i have a good amount of my savings account invested in that $20,000 because my father understands that if he is going to get me an expensive vehicle, i need to appreciate it more than just as a toy so that I am NOT reckless with it. I also have paid for all of the upgrades/changes myself and would be paying for both the lift and any upgrade from my stock tires... Don't assume that just because you attacked me i'm going to bite back kicking and screaming... It's a v6 2 wheel drive, so obviously it's not exactly a trail runner, and i understand that! I want it lifted so that i can enjoy driving and looking at my car even more than I do now, because yes, it's going to look a heckuva lot better if i do! Remember that not everybody lifts their car just so it can be more trail-ready. That's why you can buy a hardened piece of plastic disk, or if you really do need an upgraded suspension, a fully-rebuildable coilover...

Honestly, if the kid wants to run the 4Runner over every mudhole he finds it won't matter if its lifted or not. I did the same thing when I had my Blazer and my 4Runner, I only invested in the lift and tires AFTER I found how limitimg the stock set-up was and that the way I wanted to drive the rig was going to damage it without the proper clearance and such.

As for playing devil's advocate, someone has to and those are logical arguments that are valid.

The facts are that if you lift your vehicle you increase the center of gravity, granted 3 inches may not seem like a lot but add in some 285/70R17's (assuming that's your tire) and its closer to 4~4.5" lift which is significant enough to cause issues with roll over.

This isn't to say that you can't minimize the potential of the vehicle rolling over, aftermarket suspension would help greatly. Particularly ones like OLW, ICON, ect that are designed for offroad use, they will help stablilize the vehicle in those situations and reduce suspension flex compared to stock components. You are also on the right track with increasing the width of your tires and track width to accomodate the increased height. It won't decrease the added potentional of a rollover completely, but it helps significantly. Just make sure after you install the kit to drive it conservitively for a bit until you get used to the new suspension and feel of the vehicle.