Although I already know for a FACT that this will not be a popular topic here whatsoever, please excuse my intrusion as I drop just a few tidbits of information here. I made these posts somewhat accidentally on the 5th generation sub-forum as they have a thread about it, and I could not easily find a corresponding thread here in the 4th generation section, so I'll start one.

With my 2008 4Runner getting older, I feel like it could get a bit more pep in it's step. Mine has over 170k and I'm the original owner (4.0L V6), but it just doesn't pull highway grades the way it used to and feels a bit tired overall. A little targeted weight reduction could possibly go a long way, but I fully appreciate that most people with these great trucks just don't think that way at all.

I do happen to think that way, but I haven't really devoted much time/effort to my 4Runner over the years to work on these ideas. Here are a few tricks that I have thought of, which may or may not be helpful to others in a similar frame of mind.

Remove OEM roof rack (if it suits your use case)
Remove OEM running boards (if it suits your use case)
Remove OEM tow hitch (if it suits your use case)
Lightweight battery (warning...this can be expensive)
Aftermarket wheels/tires (stock must be reasonably heavy, but this will likely be $$$ too)
Aftermarket lug nuts for wheels

I'm less clear what the stock equivalent parts weigh on this vehicle though, so it's much harder to just declare victory on anything without knowing what it weighs. Even though I'm a weight weenie when it comes to performance, I'll also be the first to tell you that some things are just not worth it.

One thing I've personally noticed is that I've fed my 4Runner 87 octane (always top tier) fuel for nearly it's entire life. It seemed to do fine on this grade of fuel, and some early experiments I ran many years ago seemed to demonstrate no noticeable differences when run on 92. However, just this year I tried again and I feel that even running 89 is helping the vehicle perform much better. This is only based on my own butt dyno and not quantifiable verified, but my butt dyno has 170k of miles of experience and it seems to be a lot happier on 89 octane now. Your mileage may vary (figuratively and literally), but that may be a way to unlock a bit more performance if your vehicle is getting older like mine.

Spare a little humor for a guy like me!

As a very small update to this thread I can now tell you guys that the OEM cross bars for the OEM Sport Edition roof rack weigh 5.5 pounds on my digital scale. Considering I haven't used them even one time in my 12 years of ownership, it wasn't a hard decision to pull them off.

If you need a tutorial video to help, I found this one here:
2006 Toyota 4Runner Sport Edition 4WD - Factory Crossbar Removal - YouTube

Without having already added weight like bumpers, skids, winch, its hard to lose weight.

From bone stock, in addition to what you have listed:

Higher-end racing seats
Remove sunroof
Replace glass with lexan
Titanium exhaust and muffler
Doug Thorley long tube headers remove cats which are fairly heavy though the headers are heavier
Remove spare tire/ spare tire cable winch, and crossmember
Rear seats weigh 84 lbs if I remember correctly from another thread

Thanks for humoring me and adding a few contributions bud, I know it's not a hot topic on these boards...but still fun for me to approach the concept with all of my vehicles. I appreciate it!

Just the other day I noticed the rear seats are incredibly heavy. Mine are leather, so probably even heavier. The cloth seats in my Prius are nearly weightless in comparison.

I can't remember if the V6 has an exhaust resonator, but that's a good chunk of metal that's not important.

If you have 4WD and can trade for a 2WD that saves several hundred pounds. Look for manual cloth seats and no sunroof. Or do a manual transmission swap from an FJ.

You could take out any unneeded accessories like the rear cargo deck (if equipped).

If you're in a frigid place you could take out the AC system, but I wouldn't do it otherwise. (And make sure to properly recover the refrigerant if you do).

Some people remove one or more sway bars with no ill effects.

I'm not sure how much different tires vary in weight, but it's worth checking. Obviously load range E or anything like that will be heavy, but I wonder if there's anything much lighter than average highway tires. For what it's worth I've been running stock size highway tires (Michelin LTX MS2) for the last 6 years, and I've gotten everywhere I want to go, on road or off road.

I think there were two battery sizes from the factory. The smaller one is probably fine for most people.

I'll bite! Weight reduction is actually hugely important to me. Especially being at the point I'm at with bumpers, winch, rack, drawers, fridge, dual batteries etc. That was my reason for going with a low pro front bumper, custom rear bumper, and smaller winch with synthetic line. I've gone with F55 aluminum fairlead and Flatlink, as well as a kinetic recovery rope and soft shackles with 2 traditional shackles in an effort to reduce recovery gear weight. I'm sure it's not much but I use a couple of Rotopaxes instead of metal jerry cans and their accompanying mount. The PO had removed the rear seats when building the bed platform and went with aluminum skids.

I'm going from a 295/70 STT Pro on 17x9 XD 301s to a 315/70 Wrangler Duratrac on 17x9 SCS F5s and should drop 10 lbs rotating mass per wheel which I'm hoping will make up for the increase in tire size.

I'm still always looking for ways to cut down more weight. My solar panel covers my sun roof so I'm considering ditching that whole assembly and sealing it up, but I'm not sure that would warrant the effort. All in all though every little bit helps.

Thanks for a little bit of love on the topic guys...definitely makes me smile!

My factory exhaust actually broke after the center resonator (mid-pipe) and although I have purchased a replacement rear I haven't had it fixed just yet. The lack of the rear muffler portion has never really been that much louder than stock, and it is a fairly significant amount of weight temporarily lost.

Let's just say I'm in no hurry to complete the repair at this point, and I'm not being pressured to do it. Haha!

For weight reduction and acceleration performance I'd go with C rated tires as they are lighter than D or E.

Get an injector cleaning service done to make sure you're motor is performing well.

This is how we did 4th gen weight reduction. Then we added a few hundred pounds of steel inside it.

Sherpa,
Do you have a build thread for that truck?

If you are not an off roader like me remove your factory skids and just replace the fuel tank one with an RCI, or other. Check out a new set of wheels and pay attention their weight, don't go with oversize tires, stock 265/65R17 are more than adequate. Install the 3 degree retard cam gears for a little more zip.
And do some of the other suggestions if so inclined.

Thank you for the excellent reply!

Saw the topic, the username, and the signature...of course it had to be the same Steve Theodore from Supraforums

How about compensating for the weight with a 2JZ swap...I'm sure you know a little bit about them

Removing all the airbags would net you around 40lbs of weight decrease. You would not believe how much the side curtain airbag barrels and brackets weigh.

If you are trying to get less parasitic drag on the engine so that you pull hills easier I would look into a custom undersized crank pulley to underdrive the accessories.

Guilty as charged, and thanks for spotting me considerably away from my natural habitat. Trust me if it wasn't for the complexity of retaining 4WD, which is of course a huge requirement of my 4Runner for wintertime driving, that would be on my wish list!

My wife would NOT be OK with airbag removal as this is the family truckster, but the underdrive pulley is a pretty great idea!