Corollas made from 1993 to 1997 had two engine choices, the 1.6 liter 4A-FE and the 1.8 liter 7A-FE (click here for many details, comparisons, and diagrams!). As emissions laws and tuning changed, horsepower figures moved around slightly, but not enough that the average person would notice: in 1993, horsepower was 110 hp at 5,600 rpm. By 1996, less peak power was available, but you could get it more quickly: 105 hp at 5,200 rpm. Torque went up by two foot-pounds in the same time, from 115 to 117.
A full description of the 4A-FE and 7A-FE engine is at the Toyoland site.
1998 models benefitted from a new engine family, the ZZ. The 1ZZ-FE engine combined substantially more power and economy with cleaner burning of fuel. It debuted with 120 hp (at 5,200 rpm) and 122 lb-ft of torque (at 4,400 rpm), which means that it not only makes more power than its predecessor, but does not need to be revved as high to do it. The result is a very fast car that feels peppy at all engine speeds. (In 2006, the engine was producing 130 hp and 125 lb-ft of torque, for reasons we will go over later on).
For details on the new 2ZR and 1NZ engines, see our 2009 Corolla section. Specs are below for comparison.
The ZZ is an aluminum block engine which uses iron cylinder liners - a common design. The deck is open, which saves weight and allows for greater precision in construction, also results in less cylinder strength, really only a problem for those who want to turbocharge or supercharge their engines with a high degree of boost. On the other hand, the bottom end has been strengthened with a full-size main bearing girdle.
The 1ZZ-FE has a fairly long stroke, which is one reason it makes good torque. The bore is 79 mm, the stroke is 91.5 mm. There are two cams and 16 valves (four per cylinder).
The heads are designed to provide knock resistance while keeping combustion efficient. Their tapered squish area design, which forces a mixture of fuel and air at the spark plug, allows for a high compression ratio of 10:1 - on regular gas.
The valve seats, rather than being pressed into the head, are sprayed on, allowing them to be much thinner than standard valve seats - the result is efficient transfer of heat through the valve seats instead of the valve stems. This allows the valve stems to be relatively thin and light, so that the valve springs can be lighter, reducing wasted power and allowing for thinner cam lobes. This also means that the twin cams can be driven by a quiet, compact single-roller timing chain.
The fuel injection is returnless, with a pressure regulator in the gas tank, to reduce fire risk and make combustion more efficient.
The exhaust manifold is short, with the catalytic converter very close to the engine. To allow this, the aluminum intake manifold was moved to the front of the engine. Long intake runners were used to increase low-rev power. Toyota uses extruded aluminum, which is smoother than cast aluminum, and made the runners fairly wide.
|Bore and Stroke||3.19 x 3.03||3.19 x 3.03||3.11 x 3.60|
|Displacement||1587||1587 cc||1794 cc||1797||1496|
|Valves||8||16||16; VVT-i||16; DVVT-i||16; VVT-i|
|Horsepower||90 @ 6,000||105 @ 5,800||126 @ 6,000||130 @ 6,000||134 @ 6,000||108 @ 6,000|
|Torque||95 @ 3,600||115 @ 2,800||122 @ 4,200||125 @ 4,200||128 /4,400||103/4,400|
|Construction||Aluminum alloy block, head; steel liners; DOHC|
|* Not sold in North America|
2000 saw the introduction of the next generation ZZ engine, which includes variable valve technology ("VVT-i" for Toyota, "VTEC" for Honda, and there are others) to raise power by 5 hp while increasing fuel efficiency by about two or three miles per gallon.
2003 saw yet another major advancement, this one in gas mileage. Though the 2003 Corolla added both weight and a little horsepower - another 5 hp, making it 130 in total with 125 lb-ft of torque - gas mileage actually increased. It would have increased more, thanks to direct injection (long used by Mitsubishi, direct injection is even more efficient because it squirts fuel right into the cylinder), but American gasoline apparently has too much sulfur to allow that; sulfur content however is slated to be reduced from as much as 300 ppm to 30 ppm sulfur by 2006. Toyota may then be the first company to put direct injection into a standard-price "large" four-cylinder engine. (Thanks for the correct, “Dom.”)
2006 saw another design update to the 1.8 liter engine for models sold in Japan starting in 2007, to be imported to the US in 2008 or so. This appears to have mainly been an improvement to the variable valve technology - namely, applying it to both intake and exhaust valves, as in the Dodge Caliber. Gas mileage is, with this system, increased quite a bit, though power rises more incrementally:
|Peak Metric Power
|2ZR-FE||1,797||100 (136)/6,000||134 @ 6,000||175 (17.9)/4,400||129||17.2||40.5|
|1NZ-FE||1,496||81 (110)/6,000||108 @ 6,000||140 (14.4)/4,400||103||18.2||43|
*Japanese measurement specification
Back in 1983, a new 1.6 liter 4A engine was introduced. The 4A had 1587 cc, bore and stroke of 3.94 x 3.03, compression ratio of 9.0:1, 70 hp @ 4,800 rpm, 85 lb-ft @ 2,800 rpm in 1983.
The 1.6 liter 4A-GE was a higher-compression (9.4:1 rather than 9.0:1), electronically fuel injected, 16-valve version of the 4A, with 112 horsepower and 97 lb-feet of torque. This latter engine used dual cams, a central spark plug (“semi-hemi”), and variable induction - a series of valves in the induction ports to improve intake velocity at low engine speed, andincrease airflow at higher speeds. An oil cooler was standard. Transmissions used with the 4A-GE were the close-ratio five-speed stick and the four-speed automatic.