2016 Corolla LE ECO

[serialk11r]

None of the mods you describe will be easy, besides the K&N filter, which probably won't do anything.

The one thing that some ecomodders do that would NOT work on your engine would be a hot air intake, because you have no throttling losses, so cold air is best.

Toyota ECUs are notoriously difficult to crack, and even if you can get in, it would be hard to find how to control the idle speed while the car is moving.

I would check under the hood and see how many wires are coming out of your O2 sensor. If there are 5 wires on each sensor, you're in trouble. If you have 4, you have to replace all the sensors with wideband O2 sensors, and use an emulator like the Innovate LC1 to trick the ECU into thinking it's running at stoichiometric when it's actually running lean, but you can only lean it out a little bit with this trick. However with 3 O2 sensors you'd be looking at something like 700 bucks for this mod.

Since your engine is already so efficient, I would just forget about modifying it. Get your pulse and glide technique down, do what you can to lighten and streamline the car, and call it a day.

The other things you can do are going to be very involved, like putting synchronous rectifiers into the alternator, an electric water pump, etc.

[GK13]

Ok. I have taken out the spare tire and Jack since I have good roadside assistance. Not sure how else to reasonably lighten it. And I have no idea how to streamline it. And why would a cold air intake help me and not others? I thought I'd want a hot air intake or a short ram if anything? It's taking in engine air that's presumably warm since I took the resonator off that went down the side of the engine. That did surprisingly help it.

[GK13]

Any reason the warm air isn't good for my car like you're saying? Idk why a cold air intake would help me and no one else.

[serialk11r]

Originally Posted by GK13

Any reason the warm air isn't good for my car like you're saying? Idk why a cold air intake would help me and no one else.

Well, the default air intake is a cold one. You have to intentionally change something to get a warm air intake.

The reason it won't help you is because your engine does not use the throttle plate. Instead, the valve lift is reduced to something like 1mm and very short duration, closing the valve very early. What that does is trap a tiny amount of air in the cylinder, and then the piston goes down and draws a vacuum against the closed valves, and then on the way back up the piston regains all of the energy used to create the vacuum. This kind of setup should use something like 50% less fuel while idling.

Hot air intakes reduce the density of the air in order to open the throttle further, but hot air is worse for thermal efficiency when you exclude the pumping work part of the cycle.

Your car is very optimized for fuel efficiency; it has a CVT, underbody panels, and Valvematic. There's not much more fuel economy to be had. You can make a trunk lid spoiler, fill in some more gaps in the underbody, cover the wheels, and then the rest is going to be expensive weight reduction.

Underbody could still use some work:


The cheapest weight reduction you can find is probably replacing the battery with a smaller AGM battery. You can probably lose 15 pounds that way for under 100 bucks, but your battery might accidentally go dead sooner. Another cheap weight reduction you can do is get an aftermarket muffler, and then have it welded in place of the stock muffler. I did this for 150 bucks using a fairly quiet 70 dollar Magnaflow stainless steel muffler and saved 20 pounds on my FRS.

The cheapest engine efficiency improvement you can find is probably a bigger water pump pulley. I'm not sure if this will fit, it might: MWR Underdrive Pulley – Lotus/Toyota 2ZZ Water Pump | Monkeywrench Racing

You might be able to do it cheaper if you take the pulley off yourself, and somehow increase its diameter. It runs off the smooth side of the belt which makes this way easier. If you can figure out a way to add a little material to the outside, that would get you a slightly slower spinning water pump that would save a tiny bit of power.

The only thing that will have significant improvements is spoofing the car into running lean like I mentioned, but that will be quite expensive.

[GK13]

Thank you so much for making that make sense to me!! I appreciate it so much. I'll probably add to the underbody panels now that I see better what is actually there. I would like to do a cat back exhaust 1. for sound and 2. for the weight reduction.

I did order the K&N drop in filter but should I have actually gotten the real cold air intake that goes down the front wheel well? Or maybe the short ram intake? Or do you think the drop in filter in the standard airbox without the resonator would be enough?

That pulley looks like something I can do pretty easy. Would doing the altanator pulley be worth it too?

I did find one spoiler that looks good and would be really the only spoiler I'd like to have on it. I have the stock factory little lip spoiler on it and I'm sure that's just for looks. How does the spoiler help it though? I always thought that they were really just for looks under 100 mph?

[serialk11r]

I don't think cold air intakes actually do anything, usually the factory air box is pretty good at pulling cold air. Often times the aftermarket "cold air intakes" actually end up sucking hotter air from the engine bay, and you have to shell out 300 bucks for them.

Alternator pulley is not worth it because it'll reduce your voltage at idle. Water pump and power steering pump are always worth slowing down a bit, ideally removed completely but that's a lot of work.

If you have the lip spoiler on the trunk already, I wouldn't bother with more aero mods.

[GK13]

I finally came up with the perfect idea for the grill block. Use drywall toggles and have it hook inside the front grill. Make it in 3 pieces so they can be removed to allow cooling in the 115+ AZ heat during the summer. I was also thinking of smoothing where the fog lights are by covering them in some sort of abs plastic or such with double sided tape. Would that help enough to be worth doing? I just thought that they grab enough air and since I don't have fog lights to just smooth them out. Now how would I slow down the power steering or the water pump? The belts are all on the side of the engine like no neighing I've seen before. So I just am clueless.

[serialk11r]

I don't think you have a power steering pump, you should have electric steering. You should have idlers, alternator, water pump, and AC. The water pump and AC are the big pulleys, but the water pump pulley is the smooth one:

[GK13]

So, just got 52 mpg on my tank with super hypermiling to the best I can and the resonator delete. I know taking that resonator off had to of done something because it goes up hills better even. I can tell because with the cruise on the rpm's are lower going up the same hills. I should have the K&N drop in filter in a couple days. Waiting on Amazon.

What would the impact be on doing smooth wheel covers or even an extreme rear wheel skirt? Thinking as far as the bumper goes down.

Talked with a muffler shop today. Said that they could easily do the swap for me. But I'd loose low end torque and a little acceleration. I don't ever floor it so does that matter much?

[serialk11r]

Originally Posted by GK13

What would the impact be on doing smooth wheel covers or even an extreme rear wheel skirt? Thinking as far as the bumper goes down.

Talked with a muffler shop today. Said that they could easily do the swap for me. But I'd loose low end torque and a little acceleration. I don't ever floor it so does that matter much?

Hard to say, people here who have done full skirts have seen noticeable improvement.

It's hard to say if you'll lose low end torque actually. Usually with a cam phasing system in a normal engine, you lose low end torque because the engine runs with a lot of overlap at low speed. With this engine, it might have less overlap because it can adjust cam duration freely.

Exhaust is obviously not going to be a cost effective mod for mpg, do the skirts first if you can.