I have done research and have found only bits and pieces of information on this subject.

I recall someone having the exact measurements (which he conducted himself) of the different model years, but his site is down, and I was wondering if anybody knew: What is the 3rd gen year to year ground clearance differences from the factory?

If I'm not mistaken, the 1999 and 2000 4runners had the highest standard clearance, and that is why they're the most desirable, with a lot of people quoting the 1999-2000 Highlander with 5-speed and E-locker to be the most desirable 4runner of all time.

But the question becomes, what are the actual differences between the years as far as official ground clearance, and also, WHY are there these differences? What was Toyota doing?

Thanks for anyone who knows the numbers! They are relevant to my interests.

Last try to see if anybody has any thoughts!

I don't know why they did that. I have a '99 4-cylinder and it seems lower than most of the other 1996-2000 4Runners I see. Mine is 21" from centre of hub to the fender

I think the Ford Explorer roll over controversy was a big reason to why the lowered it. For what it's worth, the difference in height is negligible at the point. The average used 3rd Gen has at least 100k on the odo and at minimum 11-12 years old. All that time and miles has taken its toll on even the 99' tall springs.

Also, the Highlander package was nothing more than an appearance package. A sport hood, fender flares, and wheels. The things that really mattered such as the 5-speed, e-locker, and tall springs could be ordered on an SR5.

I'm thinking you we're looking for Darren Kilgore's site mycolorado.org
It went down last year some time for reasons that I'm not aware of. I've even tried contacting him with no luck. I hope he's doing ok.
This link might help you.

Height measurements, help wanted

'99's were tallest, but 2000's were the lowest standard height (Ford Exploder fallout). Most '99 SR5's with 16" wheels from the factory got the same tall springs as the Highlanders (including mine). I still run my original springs with new Tokico shocks and I'm dead level. Never towed and never had much weight in the back.

I thought the lowest years were 2001 and 2002?

Actually, this can be solved if there are any stock 4runners out there - could you measure your clearance at your front differential? Just state the year, model, and minimum clearance.

The clearance at the differential should be the same for everyone since it's determined by the tire size, right? The differences between the models is primarily from the springs, so you'd have to measure something that's impacted by spring height...so like, the frame, maybe?

Feel free to correct me if I'm wrong.

Front is IFS so it is impacted by spring height.

What is IFS?

Can't people with the model year sales catalogs just look it up for the year catalogs they have? I have the 98, just not on me at the moment. I'll see what it says when I get home if I have time.

Independent front suspension

OK. Coming from the Wrangler world, I'm more familiar with solid front axles (SFA). I thought the IFS might have meant the front diff was affected by springs, but I wasn't sure. But now I know!

It would provide pointless results.

All 3rd gen 4Runners with stock springs will have experienced some sag at this point. How much will depend on how it's been used, and can only be determined by measuring the current clearance, installing brand new springs for that specific model and year, and then measuring again to find the difference.

Every vehicle would also have to be running the exact same brand-new tire, at the exact same inflation pressure, to have any validity.

There's also the curb weight variable between different models, that could be taken into consideration too. But we'll ignore that for the sake of keeping it simple.

Everyone seems to be on different pages:

The lowest point (what true ground clearance is measured by, e.g. the tallest object you can drive over without scraping anything) is the rear differential. It is ONLY affected by tire height because it is a solid axle (SA). The front differential is part of the independent front suspension (IFS) where the height to the differential is affected by lift/spring height as well as tire height--however this is not what determines ground clearance because it is NOT the lowest point (that's the rear diff as stated).

Taller springs help approach/departure/break over (the steepest angle you can approach/depart without the bumpers hitting, and the sharpest angle you can go over without getting high centered). This can be measured and calculated with simple trig from the height of the front/rear bumpers.

So in summary, actual ground clearance isn't changed among the years because it is a factor of tire size which is independent of vehicle height. The angles however are changed.