2006 Corolla

[ps2fixer]

So I picked up an ultra cheap 2006 Corolla that was riced out with a ton of little problems (almost everything fixed now).

Based on very rough estimates, looking like I'm hitting somewhere around 40mpg so far on this first real tank which is quite good. I more or less wrote off the 1zz engine as being bad for mpg with my bad mpg experience in a 2003 matrix (33mpg on a long trip and slow speeds).

Anyway, currently have stock sized tires back on it, removed wheel spacers. The last owner hit a deer and removed one of the fenders so it's a nice air catch I'm sure and the bumper skin is broken on that side of the car too.

I'm enjoying the manual trans, engine seems to run really well at 3-4k rpm shifts, mpg wise it seems to prefer roughly 2000 rpm.

One thing I find really strange with this one is the gearing. 60mph is basically perfectly 3000 rpm. I talked to a matrix owner with the same engine and manual trans, and her car goes 65mph @ 2800 rpm, so clearly a lot higher geared on that one. The last owner mentioned the engine was replaced which can be hard to trust, but I wonder if they swapped the trans out at the same time or something. Speedometer lines up though so kind of a weird thing I've noticed.

Based on a little googling, this car should have the C59 trans, this page says corolla and matrix should be the same gear ratios. Google results suggests the tire sizes should be more or less the same between each model.

https://www.mygarageiscoolerthanyour...-series-ratios


This car did come with ~8% oversize tires and it also has a lift (sort of a rally car style setup). I want to get some base line driving done on stock sized tires, then try the over sized tires to see how that effects things. In the past I've generally seen mpg increases with larger tires.

The engine seems to be the happiest roughly 2000 rpm, I can drive slower speeds down to around 1500 rpm, but it seems to effectively start lugging around that point (~35mph in 5th) where mpg falls off a bit, or it's just my foot/road conditions. It seems like 40-50mph is roughly the ideal speed to travel for the best mpg in it's current state, but even driving 60mph doesn't seem to drop mpg too much. Scan gauge showed 38mpg to a location, and on the way back I drove ~50mph for most and 40-45 mph for ~4 miles and got an indicated 44mpg on the scan gauge.

Anyway, big wall of text, but found the transmission situation really strange on this one, but it seems to like the higher rpm a bit almost like it's a 2zz, but everything I can find it appears to be a 1zz.

FYI, last time I was really big into mpg was with my 97 corolla 1.8L auto trans, got 38-44mpg with very little mods, just max sidewall tire pressure, ~1/2 engine belly pan, lower grill block off, and passenger mirror delete. This car seems to be pulling similar numbers roughly while being rusty and the body being far from ideal including the giant spoiler on the back (maybe it's helping some how? It is roughly where I'd expect the air to coming off the roof line would hit, the down force effect of course is a waste being fwd lol).

I'll have to get some pics of it. Kind of funny last owner said they couldn't afford to fix it, they had all new brake parts, new fenders and hood, yet the major brake issues with it cost all of $28 for a wheel cylinder and $7.50 for a caliper pin set (one bolt was broken off), some people's priorities I guess lol. I even fixed the wipers.... just had to install a fuse, and the 100 amp alt fuse was destroyed so pulled that off a parts car I happened to have. It does have a charging issue which seems to be brushes in the alt, got a reman on it's way, big $65 shipped wholesale close out pricing from rock auto =).

Oh, I've noticed newer toyota models seem to love to dump a ton of fuel during cold start (more so than older vehicles). I've read it's an emissions thing which really hits my tundra's mpg bad, but this corolla it seems to either not be enabled, or it's a lot shorter of a run time. I think my 03 matrix had the tundra effect though where it got terrible mpg for the first 3-5 mins.

This corolla has like 265k on it (I don't really care about miles much), paid $350 + $50 for the extra parts. I'm torn on what to do with it ultimately, but the mpg is looking nice and it's not rusted out, so might have to keep it besides loving the fact it's a manual lol. It has the look with the over sized tires and wheel spacers that a lot of the youth would love, so I suspect it could be a fairly quick sale if it's mechanically sound and a nice profit.

EDIT: added a pic. Rear tire was the oversized tires, front is the newer smaller sized tire. That's the "good" side lol. Yes headlights are right on the ground.

[redpoint5]

It astonishes me when people mod an economical commuter car. I get why people might do that with a Supra, but the point of an eco car is to be economical, not sink a bunch of money into ruining it.

Seems like a heck of a deal. I just sold a 2003 Camry with 215,000 miles on it for $2,000.

Don't know what the deal with the gearing is, but it seems like a high RPM to me. Maybe that's just what it takes to get sufficient power out of the 1.6L at cruising speed.

[ps2fixer]

It's a 1.8L 1ZZ engine, around 130hp. My old 97 corolla 1.8L 7A was around 110hp, this thing is a lot faster than the old one though mostly because of the short gears in the trans.

The 1ZZ also has vvt, so I suspect the low rpm area of the cam prefers higher rpm, since it's a long duration cam, while the older engine was a short duration but high lift (just guessing).

The old one really did love the lowest rpm highest gear, there was some sort of weird bug with it where it would pull timing in just the right situations and I got awesome mpg out of the old corolla. Sort of remember like 39 deg advancement for "normal" driving at 45mph, vs ~26 deg advancement when I was in the weird mode that really boosted the mpg.

I haven't really watched this one super close, but the tiny I looked at timing it seems to be doing the 38-40 deg advancement at cruise.

On the rally car mods stuff, I think they were going for cheap car modified to look "cool". It actually does look kind of neat in person, just isn't really my style. I do like the lift though as I do like to go off road sometimes (I actually took the car out in the trails a few days ago and it performed well). I took my 97 off road too as it was also a cheap beater car, like $650 into that one.

I actually make harnesses for a living for the demo derby market, so tempted to slap an aftermarket engine management system in it and see if the OEM tune is really holding it back for MPG. Thing I don't like about it is it's drive by wire, but with an adapter and the aftermarket computer, that could technically be converted somewhat easily. The whole VVT stuff would be an area the cheap computers I don't think can control, so would probably need like a haltech.

I've always thought it would be interesting to tune a computer purely for MPG and ignore max hp output logic. Clearly have to keep things in safe ranges as far as going lean and such. Of course need to build a base line before any of that anyway.

Anyway, I figured I'd probably keep the riced out stuff on it for when I resell it. The guy said he paid $3300 for it before he hit the deer and I hope the brake issues and such was after he was driving it. Lots of neglect on this one for little repairs, but the oil does look somewhat fresh.

I just fixed the passenger window regulator issue last night, one of the arms was bent really badly and popped out of the slide on the window. Got it all back together and happy, lubed the window slides and it works like it should now, free repair, just had to get into it and see the problem lol.

Off the top of my head the main issues left are:

• Fender/bumper skin
• headlights pointed at the ground I think it's the whole housing, not an adjustment issue)
• charging comes and goes (reman alt on it's way, should be here tomorrow).
• One bulb in the heater controls is burnt out, so probably should replace that.
• Headlight wiring was scotch lock modified for halo lights, gotta remove those, cut the wiring and splice back together the proper way, got the nice green corrosion going on already.
• Cabin filter (I'm sure it's nasty)
• Air filter - it's pretty dirty

[ps2fixer]

So interesting results with a bit of different driving. I drove more normal around 50mph to town for most of it, bit more coasting, shifting sooner which does seem to help slightly on mpg and got around 43-44mpg on the scan gauge (not calibrated). I drove to an out of town store roughly the same driving pattern and results.

Then the drive home I wanted to see what the max in theory with the current car's setup could get. Drove through the little country town, 35mph and notice it's in the 50's which was better than I was seeing at 45mph, so I drove most of the way home 35mph, some spots 40-45 due to traffic and hit 53.4mpg when I parked it. This car seems to respond well to slower speeds, but with the messed up front end, riced out body work, it does make a lot of sense that the areo is probably pretty bad. I did get on the express way, 70mph and in cruise was riding around 33-36mph, EPA says highway rating is 37mpg, so I think the areo of the car is a fair bit worse than factory.

I mapped a graph real quick and it's pretty interesting that the speed vs mpg in 5th gear seems to be quite linear.

35 - 60mpg (maybe peaks of 65, I didn't test average at speed warmed up for these figures)
45 - 50mpg
70 - 35mpg

There was one spot where I shifted down to 4th around 30mph and was still seeing around 60's but it was a short run. It would be interesting to measure mpg for each given speed and in gears that make logical sense for each speed to effectively map the most ideal gear to be in, in basically perfect conditions

Data logging this info would be a lot easier and more detailed with an aftermarket computer, big time if I could coordinate the data with GPS data for speed + elevation. Maybe that could be a fun little project to try to get working for my first stab into OBD2 communications.

I think it would be interesting after the base line info is collected, try the over sized tires and see their effect. Two are pretty bad but they do hold air, they just have really bad flat spots.

My current guess, fixing the front, removing the body work including the spoiler and running the oversized tires probably would give the best mpg results for the higher speeds I'd like to travel (45-55mph in most situations).