Or at a Pep Boys or equivalent. They seem to be 7 bucks for two, which can compress one spring, so the test would set you back 28 bucks plus tax.
My car expert told me that this is fine for a temporary test, but not a permanent solution. Someone else said to be carefull not to scratch the springs when you do this (to avoid weakening them?).
Zip Ties sound cool too, but maybe you would risk scratching the spring when you try to cut them off. Would you melt them off? I wouldn't like to be in the wheelwell trying to get them off when they go "SNAP!".
I've used the metal variety in the pic above ^^^ on an '83 Dodge . Had them on for over 80k ! Worked just fine.No spring breakage . No poor ride quality.iirc the springs got scratched all to heck when I installed them too. That said, I didn't know as much then as I do now though
So could they be used to lower the front of a Yaris 1" ?
Why not? The best thing is, you could do a coast-down test or whatever you like to prove/disprove the springs. Since I think it would be easier to take them off, you could put them on at home, bring the right tools with you to some empty dusty road, do your MPG test with them on, take them off, and do your test with them off.
Other people have even used rope to accomplish the same !
I had those on a '74 Capri (In 1978, I'm old) the largest drop I could get was about an inch. Not really a big change from an aero standpoint, but the car did look better. They are kind of a pain in the lower-lower back to install. Barely worth the work, in my experience.
Check a junkyard for an extra set of springs, (probably about $50) and talk to your mechanic about cutting off a couple of coils with a grinder (NOT A TORCH) and slapping them on. It'll probably only be about an hour and half labor, or $50. But since you'll have the experience of taking them off in a junkyard (an environment where your you learn without wrecking your ride home) you might just put them on yourself. It's not rocket surgery.
You'll still have your old springs (scratches can weaken some springs, and yeah some springs do break. My 260E and one of my TR's broke springs. It's rare but it makes a really scarey noise) and your mechanic might even switch 'em back for no charge if you show up at the shop with a pizza and a 6 pack.
"If you want to save gas I suggest you permanently remove the drivers seat and steering wheel. That seems to help." -Oscar Halverson