anything comparable to vtec?

[aardvarcus]

Originally Posted by PaleMelanesian

We have to compare gear ratios, not just number of gears. The 6-speed's 6th gear actually turns a few more rpm at speed than the 5-speed's top gear. I don't doubt the 6 is a better transmission, but it's not going to be any more fuel efficient.

C59 5-speed
5th: 0.815
Final: 3.941
Combined engine-wheel ratio: 3.212

C60 6-speed
6th: 0.725
Final: 4.529
Combined engine-wheel ratio: 3.284

source: 2004 Toyota Matrix Gear Ratios



Does that high compression require premium fuel? That's an added expense. I doubt the per-gallon savings outweigh the extra per-dollar cost.

That is completely true about the combined final drive and overdrive ratios, however many 1ZZ engines such as the ones in the Celica GT 5-speed actually came with 4.312 final drive ratios, resulting in a 3.51 combined ratio. Thus a 1ZZ Celica in 5th is spinning faster than a 2ZZ Celica in 6th.

The best option for pure MPG is a rebuilt with a 3.941 final drive ratio and a 0.725 overdrive in either the 5 or 6 speed.

[PaleMelanesian]

Gotcha. I was looking at the Matrix ratios and didn't realize they had different ones in the Celica. Not surprised, since it's the sporty car of the family.

[serialk11r]

Originally Posted by PaleMelanesian

We have to compare gear ratios, not just number of gears. The 6-speed's 6th gear actually turns a few more rpm at speed than the 5-speed's top gear. I don't doubt the 6 is a better transmission, but it's not going to be any more fuel efficient.

C59 5-speed
5th: 0.815
Final: 3.941
Combined engine-wheel ratio: 3.212

C60 6-speed
6th: 0.725
Final: 4.529
Combined engine-wheel ratio: 3.284

Well from the perspective of someone who drives in the city and heavy traffic a lot, the closer gear spacing is quite beneficial. On hills I'm glad I have the 4.3(12?) final drive, and my car is the lightest of the ZZ engined family excluding the Lotii. 3rd gear makes you roll a little too fast in the parking lot or heavy traffic, I always find myself wishing for shorter 2nd/3rd gears in these situations for more flexibility in controlling my "crawl". Additionally, the rpm drops are a bit big on the 5 speed and so it's easy to drop the rpms low and the have the car run out of breath.

That said, 4th gear from the C59 (about the same as the C60's 5th) is perfect for 25mph roads, as 1500rpm in 5th on the C56 makes the engine struggle a bit even if it doesn't audibly complain, but I think the C59 needs shorter gears 1-3.

If it were me, I'd take a 4.3 6 speed with 0.725 6th, with the 4.3 1st gear seems plenty short, but not sure I'd want to go down to 3.9. I like to drive slow so I'll be grateful to be able to cruise at 2700rpm instead of 3000 (that's ~55mph).

Actually fun fact, the Lotus cars have much larger wheels so even with 4.5 final drive and 0.815 6th, they spin *slightly* slower on the highway than C56 equipped cars. Only Honda has a more idiotic idea of what a highway cruising gear should be (see Integra GSR, S2000).

[PaleMelanesian]

Originally Posted by serialk11r

If it were me, I'd take a 4.3 6 speed with 0.725 6th, with the 4.3 1st gear seems plenty short, but not sure I'd want to go down to 3.9. I like to drive slow so I'll be grateful to be able to cruise at 2700rpm instead of 3000 (that's ~55mph).

Actually fun fact, the Lotus cars have much larger wheels so even with 4.5 final drive and 0.815 6th, they spin *slightly* slower on the highway than C56 equipped cars. Only Honda has a more idiotic idea of what a highway cruising gear should be (see Integra GSR, S2000).

Add Fit to that list. MPG is no good past 45 mph, and 60 is 2800 rpm. In what they call an economy car. It's not quite as bad as the B-series cars but those are meant to be sporty.

[serialk11r]

Originally Posted by PaleMelanesian

Add Fit to that list. MPG is no good past 45 mph, and 60 is 2800 rpm. In what they call an economy car. It's not quite as bad as the B-series cars but those are meant to be sporty.

Well, Yaris is just as bad to be fair lol. 2800rpm at 60 as well. Sadly, with a transmission swap my car would be at the same revs/mile, so in my eyes they have good gearing! Is it too much to ask that the revs stay below half the rev limit while going the speed limit?

Sad thing is, Fit/Yaris are still being made with those lousy 5 speed transmissions. Hyundai gives you a 6 speed for their cheapest turd-pile. And while the 1NZ is alright, it's been 13 years and we can use some new features and combustion chamber design...Honda just got the balling rolling with their new K and J engines, your turn Toyota.

[type-S EF awd]

Originally Posted by PaleMelanesian

I believe the Toyota 1zz and 2zz equipped cars should be as capable for mileage as the Hondas. I almost bought a Matrix last month.

Sir, I dont think you have real world data on the toyotas. the ONLY time I've seen a toyota out perform a similar honda in fuel economy is with their far superior hybrid system. Honda's economy vtec has a low switchover indicitive of low RPM economy, no early model toyota has this. Most importantly, is the MT gear ratios toyota offers.

With a manual transmission you have to downshift for sudden acceleration, as drivers are assumed to be dumber with each generation, it is assumed we wont be able to react with: clutch in, rev match throttle blip, 1 or 2 gear downshift, clutch out, heavy throttle.
So a fairly short final drive is installed so in top gear, there is "adequate" acceleration.

With automatics, a downshift requires no drivers input other than rolling into the throttle. Therefore with modern 5, 6 , 7 and 8 speed autos, and multiple stages of lockup, the manufacturers are comfortable releasing a car with a tall final drive ratio. My wife's Venza is a good example, its a large car, with a 4 cylinder engine, yet at 65MPH its at about 2000 RPM.

This is why despite the higher weight, and parasitic drag of a fluid pump, automatics are often rated higher in highway MPG

Honda with the 84-91 CRX HF, the 92-95 civic VX and CX have very tall ratios, .694 5th, 2.954(federal emission HF) and 917 Rev per mile tire put the car at 64MPH at 2000 RPM, slower than my wifes Venza example. And if you've ever driven one of these, they are VERY different starting from a stop.

the venza numbers if your curious are .608, 4.356, 703

The accord F22B1 was an economy vtec engine commonly overlooked because the 5th generation accord was not particularly lightweight or aerodynamic, and it was not given such tall gearing, 2000 RPM 5th gear yielded 51MPH

[oil pan 4]

If you want variable engine power, low speed efficiency and high compression.
You might want to think about a turbodiesel.

[serialk11r]

Originally Posted by oil pan 4

If you want variable engine power, low speed efficiency and high compression.
You might want to think about a turbodiesel.

aaaaaand where are we supposed to get one?
Today I drove 1.5 hours running to various places and I saw exactly 1 diesel car, and it happened to be belching smoke.

[mechman600]

Originally Posted by serialk11r

aaaaaand where are we supposed to get one?
Today I drove 1.5 hours running to various places and I saw exactly 1 diesel car, and it happened to be belching smoke.

LOL...it's true. I'm happy burning more fuel with my gasser, realizing I'm not killing people with diesel-like high NOx emissions....

[oil pan 4]

Diesel passanger vehicles wont emit smoke unless they are modified or very neglicted.