I'd like to make a strong recommendation to look into using a sealant and topping it with a wax after a few days/weeks.
Sealants make an actual chemical bond via polymers to your paint; they will far outlast any wax on the market.
Here's an easy to use sealant...
This is a service I offer, I have not done this on any Toyota. We don't advertise it too much, as it is extremely expensive, but to date we've done 9 cars. Porsche, BMW, Ferarri, Jaguar and 2 Nissans (GTR).
On a car like ours, I wouldn't worry about it. The only way I can see you getting better fuel mileage is by making a hot-air intake. AKA Grab the air from just over the exhaust manifold to cause a slightly leaner condition and be more efficient.
In this case... stock > *
I use a lot of Meguiar's Detailer grade products, especially for cookie-cutter detailing jobs; quick in-n-outs.
Donabed; check out Shine Supply. They're out in CA and make some absolutely great products.
I'm willing to bet I'm a member of a few other forums they own and it's standard practice for them to do things like this.
Please let me know if there is anything I can do to help on behalf of corollaforum.com; which I'll now begin referring to as CF.com
FYI I have a lot of forum experience ;)
I'm going to reach out to a local company I know about manufacturing some springs for these cars. They are top-notch quality and they are a part of a parent company that creates springs for NASA.
2012 Mustang GT Premium. Was a bolt-on and nitrous drag radial car that was a consistent 11.7x @ 121 (10.78 @ 129 on spray). Needless to say, it's a bit of a change for me.
In all seriousness, I regret leaving the Mustang. I have only put 6,000 miles on the Corolla since I purchased it in...
My combined averages have varied from 34-39mpg. On a long road trip I did see 43.1, however upon my destination it's an 11 mile island of stop/go traffic and it drastically reduced it.
I don't agree with this method at all. I've been into autocrossing and drag racing for years and can say this is the method most have had cause a moneyshift...
Best explanation I can use is summed up by turnfast.com