Discovered the 2nd row seats are 124 pounds. That weight is for seats that belong to a generation newer Sienna, but probably close enough for estimating the weight for our purposes.

I'm guessing the 3rd row, which is not normally removed, because they fold away into the floor, are, at least, 75 pounds.

That means, to keep the vehicle at it's factory weight, I have about 200 pounds of RV conversion to play with.

With DraigFlag's suggestion of an air mattress and making any cabinetry from corrugated card board, I think I can easily keep the RV conversion to under 200 pounds. This includes my 30 pound folding Mobiky bike.

Thanks, Janet! I'm quite surprised all the other RV conversions seen on YouTube still use heavy wood. How come they're not as smart as us? ;)

Just discovered the perfect solution for my RV bed; an air mattress that was originally designed for backpackers.

User reviews are excellent.

By getting the below model, I can fold in a way to provide a "sofa" back and seat cushion during my waking hours.

Lightweight Double Air Pad Â*Â*/Â*Â* ALPS Mountaineering

Keep up with your thoughts on this topic, everyone! It's helping a bunch. Doug in California. :)

In the absence of Sienna specific data, Honda Odyssey owners are reporting their 3rd row seats, which fold down into the floor like the Sienna, weigh 120 pounds. That gives my RV conversion a 244 pound budget.

With my 30lb folding bike, plus the 10lb backpacker air mattress, that still gives me another 204lbs. Should be easy to stay under that EVEN with my personal items.

Google pocket projectors Doug, I'm sure there's a handy one that will suit your needs, check the reviews of course! Are you going to strip any other interior parts? Carpets, plastic trim etc? If there's a spare wheel you could substitute it like most car manufacturers do now with a deflation kit instead. You could use the wheel well for storage then, and you'd save weight.

The pocket projectors at 0.4lbs don't throw enough light. The projector with a much brighter picture is well worth the extra 1.4lb.

Here's a great projector comparison website:

Top 10 Pico Projectors

Don't plan to strip the original parts at this time. That might be too radical, in case I decide to sell. Not looking to go crazy with chasing MPG by gutting the vehicle. Just don't want to ruin the original MPG.

I read the Sienna spare tire hangs under the mini-van. For my peace of mind, it can stay.

It's 3am-ish in the UK. Go to sleep, for gosh sakes, DraigFlag! :)

Really? What time zone are you looking at? We are only 5 or 6 hours ahead so it's actually 8.19 pm at the time of this post ;)

I'm in California, which is - 8 hours, Greenwich time. WAIT a second! That's right. I'm 8 BEHIND you. In other words, you're 8 hours ahead. I was subtracting. Yes. It is 8:22pm for you. Carry on. :)

You might want to measure the interior space yourself. The manufacturers don't all use the same method.

https://www.cars.com/articles/2014/0...dec9d3cfa052f7

https://farm4.staticflickr.com/3747/1...e2072f37_b.jpg

Thanks, TrollBait! That was an eye opening article. Looks like the ONLY way to confirm the space is with a tape measure. I appreciate the heads-up. Thanks, again. - Doug :)