[YesAuto original test drive] Subaru, a highly personalized car brand, is well-known in the industry for its horizontally opposed engine and symmetrical full-time four-wheel drive system. The impressive record on WRC fully reflects its powerful strength. However, few people have noticed that the basic technology of the second-generation horizontally opposed engine currently used by Subaru was born in 1989. The age of more than 20 years is completely regarded as the old man in the automotive industry. The good news is that the new first The third-generation engine has been assembled on the 2011 Forester, and will gradually arm all Subaru models. This time I came to Harbin to participate in the ice and snow test drive. The 2011 Forester was used, and the editor was able to have a close contact with it for the first time.
● Appearance and interior changes
Let's take a look at what changes the new Forester has made in the exterior and interior design. Although changing the engine is a major operation, the designer does not seem to want to show the world through external changes. There are not many changes, obviously there are three.
The front face grille has been redesigned. It doesn't look good or looks ugly. Functionally speaking, it is a trivial change, just to reflect the identity of the new model.
In contrast, the appearance of new wheels makes people’s eyes brighter. The form of five groups and ten frames is more tense. The tire size of the 2.5-liter model is 225/55 R17, and the 2.0-liter model still uses the old wheel, and the tire size is 215/ 65 R16. The last obvious change is the integrated turn signal on the exterior rearview mirror, which has been a popular practice in recent years.
In the interior, the new Forester adds some practical configurations, such as color display, reversing image, automatic zone air conditioning, etc., so the visual changes are mainly reflected in the operation panel of the center console.
This 2.5-liter automatic luxury version for the test drive is equipped with a new color display, integrated with the reversing image function. When reversing, the auxiliary line displays the distance in three colors of red, yellow and green, but the screen size is relatively ordinary and it is not a touch screen. The humanized experience is not outstanding among Japanese cars.
A new model called S-Edition has been added to the 2011 Forester car series. It is equipped with a high-power 2.5-liter turbocharged engine and a 5-speed automatic transmission. The maximum power is 193kW and the peak torque is 347N·m. The unique identity is not only the engine and gearbox, but also the exclusive interior design, wrapping the seat, instrument panel, etc., and it is also equipped with steering wheel shift paddles.
● Engine changes
The second-generation engines currently in service on various Subaru models belong to the EJ series, and the third-generation engines are named the FB series, including the 2.0-liter displacement FB20 and the 2.5-liter displacement FB25, which are different from our habitual thinking. The upgrade focus of the FB series is not the substantial increase in power performance. According to the manufacturer, its main improvement lies in “improvement of control convenience” and “improvement of environmental performance.”
|Comparison of cylinder bore and stroke data of the second-generation (EJ) and third-generation (FB) horizontally opposed engines|
Engineers modified the bore and stroke of the FB series, and obtained a more compact cylinder structure by reducing the bore and extending the stroke. On the one hand, it can improve the explosive performance of the engine in the low speed range, and on the other hand, the small bore and long stroke design makes combustion It is more thorough and improves the cleanliness of exhaust gas.
Also in order to achieve a more compact cylinder block structure and effectively reduce the size of the engine, engineers reduced the angle between the intake and exhaust valves of each cylinder of the third-generation engine from 41° to 27°. The power output is more linear and smooth. In addition, the improvement projects of the FB series also include replacing the timing belt with a timing chain, upgrading the dual VVT variable valve timing technology, updating the exhaust gas circulation cooling system, reducing in-cylinder friction loss, etc., and finally the third-generation horizontally opposed engine Its power has been slightly improved, while fuel economy and emission indicators have also been significantly improved.
This test drive edit uses the 2.5XS automatic luxury model, which is equipped with a 2.5-liter naturally aspirated engine. From the parameter point of view, the maximum power value has not changed, but the output range has been advanced from the original 6000 rpm to 5800 rpm, the peak value The torque increased from 229N·m to 235N·m, and the burst interval was also advanced from 4300 rpm to 4100 rpm.
● Ice and snow test drive
In fact, I even hope that this test drive can be carried out on ordinary dry roads. It is not that I am not interested in snow and ice test drives, but I want to experience the strength of the new engine more carefully. After all, on low-adhesion ice On the surface, it is impossible for you to test the vehicle with the daily test drive method.
Except for S-EDITION, all Foresters continue to use the four-speed automatic transmission. This is really a configuration that makes people sleepy. Fortunately, there is basically no chance for you to focus on the frustration on the ice and snow road. For the time being, I will bear it. .
The test-driving vehicle did not change to studded tires. Instead, we chose ordinary snow tires. Its grip is higher than our usual tires, but it won’t be as abnormal as studded tires. The advantage is that this allows me to A small high-speed “out of control” within the range, after proper correction, a beautiful drift is completed. The high speed mentioned here is relatively speaking. The 60km/h speed on the straight road on icy and snowy roads is already very exaggerated. In fact, speed is the core of all skills. Maintaining a proper speed can effectively avoid understeer and oversteer. Don’t fantasize about it. The WRC riders are flying by, so let's start with the basics.
First of all, there is no need to introduce it in a straight line, just remember not to run wild. Immediately after we enter the corner, we need to release the throttle to reduce the speed before entering the corner, and choose to cut from the outside. If we steer according to the driving method on dry roads, we will make the first mistake: the vehicle will understeer out of all likelihood. This is because the tire adhesion on the ice is very small, and then the novice will turn into the corner. And increased the throttle, hoping to make up for this mistake, which caused the second error: oversteer appeared immediately, so it is not difficult to see that some cars parked sideways in the first corner, embarrassing.
The correct method is to control the speed before entering the corner, and then slow down the steering in a gradual manner, so that the tire grip is maintained as much as possible. The action of stepping on the accelerator must also be slow, so that the engine can output power in a stable state. Oiling or sudden pine oil can cause loss of control. On the basis of choosing the correct route, cornering in this way will basically not make mistakes.
The most interesting part of driving on ice is that the way of communication between people and cars is no longer straightforward. The lack of grip makes it difficult to get the expected response to your operation. As mentioned above, you are obviously turning the steering wheel. But the front of the car does not move according to the predicted trajectory. The conventional response is to increase the steering action. Then oversteer is unavoidable. You can only fumble forward. The driver seems to be playing Tai Chi with the car. Understand, try to find where the controllable range is, and gradually master the knack of action as you make turns again and again, and then raise the limit again and again, which is very interesting.
After passing the difficulty of understeer, the next problem we have to solve is how to correct oversteer. I believe everyone knows the way, that is, stop oiling and reverse the direction. In the previous driving training articles of Audi and BMW, I have introduced the specific method in detail ( click to view ). The treatment on the ice is basically the same, but because the adhesion is much smaller, your counter-attack action must be faster. “Rescue” the direction before the vehicle is completely out of control. Due to the existence of the symmetrical full-time four-wheel drive system, it is not difficult to drive the Forester to complete these actions. After learning the basic methods, always remember to maintain a gentle driving style.
The full-time four-wheel drive system makes the Forester’s limit on the ice much higher than expected, which also reduces the difficulty of driving to a great extent. After a period of practice, basically every driver can maintain a steady posture. Going through a corner calmly, we usually say that rear-wheel drive is more fun to drive, but the snowy road is definitely the world of four-wheel drive. If you want to have fun here, let four tires help you at the same time.
Every winter, major manufacturers will hold ice and snow test drive activities. I believe you have seen a lot of them in the car home.