The 2nd Period of Chaichefang Wide Gap between Tiida and Golf2013-11-26 中文版
Chaichefang---”The 1st Automobile Deconstruction” event was initiated by chexun.com in Dec. 2011. According to the plan of one period per month, chexun.com held the release meeting of the 2nd period of Chaichefang in the Auto Laboratory of Tsinghua University on Jan. 14, 2012. The deconstructed models in this period are Dongfeng-Nissan Tiida and FAW-Volkswagen Golf. The most test and deconstruction operation was carried out by the experts and professors of Department of Automotive Engineering of Tsinghua University.
Both Tiida and Golf belong to compact hatchbacks and are positioned for family purpose. Due to their advantages in brand and quality, both models have gained a good market response after launch and achieved a remarkable sales volume, especially the Golf, which has been in tense supply and in some regions, should be picked up after queuing for several months or even at additional price increase. Then, what the interior workmanship of the two hot-sell models is, whether they are cost-effective and if their safety guarantee are adequate will be answered by the 2nd period of Chaichefang, chexun.com.
Overview of Deconstructed Models 1: Background
Tiida brand belongs to Nissan Motor Company. This company has achieved good car business performance from Roketsan, Bluebird to Sunny. However, when Sunny was introduced by Dongfeng-Nissan in 2003, the response was not good. Then, Dongfeng-Nissan introduced Tiida models in 2005, which are three-box and two-box models using the same chassis. As their prices are moderate, both have achieved good sales performance. In 2011, Dongfeng-Nissan utilized Sylphy chassis to introduce 2011 edition Tiida. In a certain sense, Tiida can be understood as a two-box version of Sylphy.
Dongfeng-Nissan New Tiida
Tiida brand uses two types of engines: 1.6 and 1.6T, and 5-speed manual or CVT and the MSRP is 105, 300~156, 800 yuan. The entry level model is a 1.6 manual comfort edition, with the MSRP of 105, 300 yuan. The Tiida car deconstructed in this period of Chachefang is of this edition.
Golf is a compact hatchback car introduced by Volkswagen Motor Company in 1974 and it was to replace Beetle that had been produced for 25 years. It is 27 years since then and Golf has developed into its sixth generation. FAW-Volkswagen introduced and manufactured the 4th generation Golf and the 6th generation Golf in 2003 and 2009, respectively.
Volkswagen Golf of the 6th generation
Golf under manufacture is its sixth generation and uses 1.6 or 1.4T engine , and 5-speed manual or 7-speed dual-clutch automatic transmission and the MSRP is 118, 800~166, 800 yuan. The entry level model is a 1.6 manual fashion edition, with the MSRP of 118, 800 yuan. The Golf car deconstructed in this period of Chachefang is of this edition.
Overview of Deconstructed Models 2: Basic Equipment
Viewing from the MSRP, Tiida is 13,500 yuan cheaper than Golf. In addition, Tiida has a wheel base of 2.7m, 122mm longer than that of Golf, and an average oil consumption that is 0.3L/100km lower than that of Golf. These advantages have enabled a good salve volume of Tiida.
With respect to configuration, Golf is equipped with a body stability control system, an electronic anti-theft system, rear-view mirror heating and traction control which Tiida does not have, and its tire and airbag configuration is better than that of Tiida. The most worth mentioning is the electronic stability program (ESP), which is a practical safety guarantee technology. Only two years ago, this technology was only adopted by medium-level cars pricing at above 200,000 yuan.
Tiida and Golf are basically consistent in performances, such as top speed and acceleration. In terms of trunk volume, Golf’s 1305L maximum space is obtained by laying down the back seats and Tiida has the same function but its maximum volume data has not been announced.
Overview of Deconstructed Models 3: Performance and Sales Volume
The versions of Tiida and Golf are roughly equivalent to each other and the difference is that Tiida has one more version: turbo charging version. Tiida 2011 is the first version with turbo charging among Japanese compact hatchbacks in China, which is equipped with 5-speed manual or CVT. It has a maximum power of 140kW, maximum torque of 240Nm, top speed of 220/205km/h and 0-100km acceleration time of 8.2/8.3sec (manual/automatic).
Golf 1.4T version has a maximum power of 96kW and maximum torque of 220Nm, lower than those of Tiida 1.6T. However, as its maximum torque occurs at 1750-3500 rpm, its actual performance approaches that of Tiida. For example, its top speed is 200km and 0-100km acceleration time is 9.6/9.5 sec (manual/automatic).
As FAW-VW’s production capacity is insufficient, Golf has been in short supply after debut and there has been queuing for car pickup in some cities and even price increase for early pickup in some regions. From the sales statistic of Jan.-Dec. 2011, the consumers buying Golf are far more than those buying Tiida, which illustrates that Golf’s consumers favor speed and manipulation while Tiida’s consumers favor space and comfort. To them, a proper power is OK. Therefore, the targeted customers of Tiida and Golf are different.
What consumers can see in buying cars is their appearance. What is their connotation? This is just the focus of the 2nd Chaichefang event.
First: Front part of car body structure
Golf’s front bumper ★★★★☆ New Tiida’s front bumper ★★★☆☆
Golf’f front wheel fender ★★★☆☆ New Tiida’s front wheel fender ★★☆☆☆
Golf’s A, B and C columns ★★★☆☆ New Tiida’s A, B and C columns ★★★☆☆
A front bumper of car is composed of two layers: plastic and metal. The outer plastic layer is in fact a shell and behind it is often foam plastic, which, in slight impact, can properly absorb the impact energy so as to avoid hard damage needing repair. In addition, it also plays a role of protecting pedestrians.
The interior of Tiida’s front bumper is supported bymetal bar and in front of themetal bar is very thick black foam plastic playing a role of buffering.
Their plastic shells have different thicknesses: 3.5mm for Tiida and 3.2mm for Golf. After removing the plastic shells, the most difference we saw was that: 1. Golf’s bumper plastic shell is attached to a metalmetal bar while Tiida’s bumper plastic shell is attached to foam plastic and behind the foam plastic is a metalmetal bar .; 2. Golf’smetal bar is of a dual-layer structure that is thick and heavy, and tthe rear layer is 2.57mm thick while Tiida’s bar ion is of a singly-layer structure, which is thin and has a steel plate thickness of 1.59mm.
Besides, there is also a great difference in the rear supports behind their bumpers. The installation disc behind Golf bumper is 1.82-2.57mm thick while that of Tiida is 1.59mm thick.
The interior of Golf’s front bumper is supported bymetal bar and there is buffering layer on both sides.
Viewing from Golf’s bumper structure, it has sufficient strength and its protection role is no doubt. However, Golf’s front bumper has a foam material protection layer only on both of sides, with the other parts beingmetal bar . In case of collision with pedestrians, it may lead to a greater injure to the pedestrians than Tiida case. This can be understood as Golf’s disadvantage.
Second: Rear part of car body structure
Golf’s rear bumper ★★★★☆ New Tiida’s rear bumper ☆☆☆☆☆
After removing the bumper shells at the tails of both cars, we saw the biggest difference in this Chaichefang event. There was a thick, heavymetal bar directly connected with the car’s big beam (an imageable call here) in Golf’s rear bumper. This follows that its structural design has fully considered the self-protection of the rear part in case of slight rear-end collision and collision in reversing.
Thick, heavy steel beam and foam plastic---Golf’s protection is more profound than Tiida’s.
There is a buffering layer composed of three pieces of foaming material in Tiida’s rear bumper shell. Such structural design, in slight collision with any object behind the car at a very slow speed in car reversing, may lead to a loss slightly lighter than that in Golf case, which is an advantage of Tiida. In a rear-end collision at a slightly higher speed, the loss may be great.
After removing the rear bumpers, we see a thick, heavymetal bar in Golf case and three pieces of white foam plastic in Tiida case.
The three pieces of foam material are float-laid in the rear without fixing to the body metal structure or wrapping. After a certain time, it is very likely to become one of noise sources.
After removing the foam plastic, we can see a raised liner iron fixed by two screws and behind the liner iron is the “crossbar” at the chassis.
Liner iron under foam plastic Beam
After removing the foam plastic, there was a raised liner iron fixed by two screws and behind the liner iron was the “crossbar” at the chassis. That is to say, in case of rear-end collision, the impact strength may penetrate the foam plastic and squeeze the body. It is only about 1meter from the rear seats, a not wide buffering space.
The foam plastic in Tiida’s rear bumper is not fixed in connection with the car body.
To verify the strength of bumper bar ion, we separately bought the bumper ion bars of Tiida and Golf and carried out the tests in a qualified professional laboratory. It can be seen from the test results that, in terms of the yield strength of front bumper, Tiida outperforms Golf, and in terms of tensile strength, Golf outperforms Tiida.
Golf’s front anti-impact beam Golf’s rear anti-impact beam
Tiida’s front anti-impact beam Tiida’s rear anti-impact beam?
A teacher is cutting a steel beam very skillfully and the sparks are exciting.
The door panel is cut with an inverted air plasma cutter.
Test Pictures: Bumper Destruction Test
Sectional conclusion: In terms of car rear protection, Golf is rather perfect while Tiida is slightly inferior.
Comparison of themetal bar s in the front bumpers ------
Tiida adopts a single layer structure, with a material thickness of 1.59mm.
Golf adopts a dual-layer structure, one thick layer and one thin layer, with the the thickmetal bar being 2.57mm thick.
After removing themetal bar in the front bumpers, the connecting materials were found to have a great difference. Tiida uses a material that is 1.59mm thick while Golf uses a material that is 1.82~2.57mm thick.
Comparison of the installation positions of themetal bar s in the front bumpers -----
Tiida’s material is thin while Golf’s material is thick and heavy.
Golf’s bumper has the advantage of dual-layermetal bar s with a thin front layer and a very thick rear layer. Such a design can effect a better staged energy absorption.
Tiida’s bumper has the advantage of thick foam material protection layer under the bumper shell, which has an evident protection role for pedestrians. Itsmetal bar is thinner and will not be better in case of collision with hard objective than in Golf case. However, this is only an impression. Car safety does not depend on the thickness of material but on the structural design. For review of safety about Tiida and Golf, please follow the follow up series reports of chexun.com
It can be seen from the data in the above table that the lower and longitudinal spaces in Tiida engine compartment are larger than in Golf case. In fact, a large space means a large deformation space, and naturally, has a better protection performance.
Sectional conclusion: In terms of car front protection, Golf is more perfect for self protection while Tiida has given more consideration to the protection of pedestrians.
Third: Door of car body structure
Golf front door ★★★★☆ New Tiida front door ★★★☆☆
After Removing the interior decorative panel of door, it can be seen that the back of the interior decorative panel of Golf door has a finer workmanship. For example, the fixing clips for soundproof felt are dense, which can effective fix the soundproof felt, thus effectively reducing noise.
After removing the interior decorative panel of Golf’s door, an interlayer of foam material can be seen.
Back of the interior decorative panel of Golf’s door
There is also a soundproof felt on the back of the interior decorative panel of Tiida’s door, but its material is common and float-set in the panel without fixing.
Removing the interior decorative panel of Golf’s door, there is still another interlayer. The dual-interlayer design can effectively reduce the exterior noise. Moreover, the fixing clips of the interlayer are also dense.
Back of the interior decorative panel of Tiida’s door
Removing the interior decorative panel of Tiida’s door, there is only a layer of semi-transparent plastic sticked to the metal structure with non-setting adhesive.
Removing all covering pieces, you can see the internal structure of doors of both cars. In Tiida’s door, there is a flat fixing bar in the upper for fixing the door steel panel and a circular anti-impact steel beam in the lower. In Golf’s door, there is a wide S-shaped steel, whose protection area is larger than in the case of Tiida.
Internal structure of doors
There are two reinforcing bars in Tiida case and one is flat and the other is circular; there is one reinforcing bar in Golf case.
We carried out separate tests on the steels (covering pieces) of the doors of both cars and the test results are as follows.
After removing Tiida’s seats and the floor tarpet, a layer of foam plastic can be seen.
Sectional conclusion: Golf’s door structure is more delicate and more comprehensive in terms of protection but its cost is high. Tiida’s anti-impact steel beam in door looks common but has a effect that is no inferior(in case of direct hitting) and moreover, has a low repair cost.
Fourth: Floor of car body structure
Golf’s floor structure/material ★★★☆☆ New Tiida’s floor structure/ material ★★☆☆☆
In the 1st Period of Chaichefang, we made flame-retarding test on the interior fabrics. According to the national standard, the burning speed of the components for car interior decoration shall not be greater than 100mm/min (GB 8410-2006“Flammability of Automotive Interior Materials”). In this car deconstruction, we did not made this test.
After removing the car floor carpet, it was found there was a large area of foam plastic under Tiida carpet. Though some foam plastics (e.g polyurethane) may be added with a fire retardant to reduce the burning speed and control the burning scope, such type of material is not optimistic for the protection of people in the car.
If “Nissan” was not printed on it, it would be mistaken as the packaging material for refrigerator or washing machine.
From the viewpoint of structural analysis, the large area foam plastic laid on Tiida’s floor may be used to level the floor so as to enable a happy riding comfort.
Under Golf’s carpet, there is a 8mm thick layer of soundproof cotton, a material similar to that used by Cruze in the last period of the event. That is to say though this material has certain flame retarding property but it is not ideal.
After removing Golf's seats and carpet, a layer of sounproof cotton can be seen.
The soundproof cotton is 8mm thick.
Cavity Wax Injection Technology
Golf is manufactured on Volkswagen’s PQ35 platform and one of the technical highlights of this platform is cavity wax injection. That means , in the interior of the body structure, the wax applies protection to the metal materials, making the body structure durable. Some car owner reflected that there were wax drops from under A column in hot summer. Though this is not a common phenomenon, it indicates there is still something remaining to be perfected in the structure sealing.
Sectional conclusion: Whose cost is higher, Tiida’s foam plastic or Golf’s soundproof cotton? This may only be answered by the manufacturers. But there is a question worth asking: Has their flame resistance reached the national standard?
Fifth: Others of car body structure
Golf roof structure ★★★☆☆ New Tiida roof structure ★★☆☆☆
After removing Golf’s interior ceiling, a 10mm thick interlayer was seen, which functions not only noise reduction in the car but also thermal insulation, thus effectively reducing the interior temperature and saving fuel.
After removing Golf’s interior ceiling, we can see a local interlayer in the roof interior.
In Tiida’s ceiling, there is no such interlayer on the metal roof but a soundproof and thermal insulation interlayer covers the back of the ceiling. The only defect is that the interlayer is thin.
After removing Tiida’s interior ceiling, we can see a white interlayer on the ceiling back.
In removing the interior decorative panels of both cars, we found that Golf’s interior materials are easy to leave a good impression on people but Tiida’s seems thin and cheap. However, from another point of view angle, Tiida has reasons to adopt thin interior materials. For example, Tiida’s A column’s interior panel has many “ribs” and it is just these ribs that make it possible for Tiida to use a thin interior decorative panel, which can reduce both cost and self-weight, a positive role.
Viewing from the back of A column’s interior decorative panels, Golf’s material quality and workmanship are evidently more delicate compared with Tiida’s.
Tiida adopts universe type snap joints for interior panels, which are easy to buy but insufficient in toughness. Generally, after dismounting for several times, such snap joints may break. If they are broken, there will be friction noise. As they are hidden behind the interior panels, it is difficult for the car owner to find the source of noise.
Observing C column interior decoration panels, Golf’s material is more particular than Tiida’s.
The snap joints adopted by Golf are exactly the same as those used in other Volkswagen models, which are more delicate and can keep well after dismounting for many times. The defect is they are not universal components and not so convenient to buy as those described above.
In terms of the snap joints for door interior decoration panel, Golf’s material and workmanship are more particular while Tiida adopts common ones.
Sectional conclusion: Though Golf is only a compact car, its interior materials are not greatly different from those used in Volkswagen medium level cars (e.g. Magoton). This conclusion would be hard to believe if we had not experienced its deconstruction. Maybe, this is one of the reasons why the prices of Volkswagen cars stay high. Tiida adopts a design thinking wholly different from Volkswagen’s and its principle is just proper for use. This can reduce the manufacture cost so as to reduce the sale price and repair price.
Sixth: Body manufacturing process of body structure
Golf’s assembly process ★★★★☆ New Tiida’s assembly process ★★★★☆
Golf’s welding process ★★★★☆ New Tiida’s welding process ★★★☆☆
One of the methods to measure the car manufacturing process level is to verify the uniformness of body seams. Measure the seams in sequence, take the maximum values and the minimum values and calculate the mean value of multiple points. The least the error, the higher the manufacturing process level. Therefore, we measured the door seam width of A, B and C columns of both cars and the results are as follows.
Seventh: Suspension and Comfort
Golf’s suspension system ★★★★☆ New Tiida’s suspension system ★★★☆☆
Golf’s comfort ★★★★☆ New Tiida’s comfort ★★★☆☆
Currently, cars mostly adopt front wheel-drive and the engine is set in the middle. As a result, the front suspension is of course of independent type. So, the key is whether the rear suspension is of independent or non-independent type. In the 1st period of Chaichefang Column, we said that car suspensions were of independent and non-independent types. Some manufacturers named their rear suspensions with various types, and they were only some improvements in performance based on non-independent suspensions. In essence, suspensions are of only the above two types.
Golf’s rear suspension is of independent type.
Tiida’s rear suspension is of non-independent type.
Golf’s rear suspension adopts independent type while Tiida adopts non-independent rear suspension. Therefore, Golf’s comfort is better than Tiida’s, which has been verified from the relevant test.
The teachers of Department of Automotive Engineering of Tsinghua University used a special instrument to test the comfort of both cars. The data displayed indicate the time for the passengers sitting on the back seats to become discomfortable at a certain car speed. The test results show that Golf outperformed Tiieda at all three speeds.
Human body comfort sensor
Sectional conclusion: Tiida has a wheel base longer than Golf’s. Therefore, the passenger’s leg space for Golf’s back seats is smaller than Tiida’s, but its comfort exceeded Tiida’s. This result was unexpected for all editors of chexun.com.
The clearance of Golf’s front door is 3.8 mm at the maximum and 3.4 mm at the minimum.
The clearance of Golf’s rear door is 3.4 mm at the maximum and 3.0 mm at the minimum.
The clearance between Golf’s front and rear doors is 3.8 mm at the maximum and 3.4 mm at the minimum.
It can be seen that Golf’s maximum and minimum values approach the mean value, with most errors within 0.2 mm. The biggest error is at the right B column, which is 0.5 mm.
Tiida’s errors between the maximum and minimum values and the mean value are great, which are around 0.7~1 mm.The biggest error is at the right B column, which is 1.3 mm.
The clearance of Tiida’s front door is 5.0 mm at the maximum and 3.6 mm at the minimum.
The clearance between Tiida’s front and rear doors is 4.8 mm at the maximum and 3.4 mm at the minimum.
The clearance of Tiida’s rear door is 3.7 mm at the maximum and 2.3 mm at the minimum.
Besides, the welding processes of the two cars are not the same. After removing Tiida’s interior panel, many welds as shown in the picture below can be seen, leaving people a sense of roughness.
Golf’s body covering pieces and doors are joined by laser welding. After removing the interior panel, the welds give a very good visual effect. The more important is that the body’s integral connection strength can be better or more solid.
In terms of the welding at the trunk door, Golf’s is much more delicate than in Tiida case.
Though common welding pieces are used by both cars, Tiida’s welding process is more like that of village iron processing shop.
There is another index for body manufacturing process—— coating thickness or paint thickness. It can be seen from the table below that Golf’s coating thickness outperformed Tiida’s. The mean thickness of wheel fender is 26μm greater, that of door is 17μm greater and that of engine compartment cover and tailgate is 38 μm greater compared with Tiida’s.
Sectional conclusion: Golf’s body fineness is evidently one-level higher than Tiida’s.
Eighth: Quality at Details
Before this period of Chaichefang event, the supporting groups for Golf and Tiida in the editorial staff of chenxun.com were in a half-to-half pattern. However, with the progress of the deconstruction test, people found that Golf, though not very perfect, has really done a more proper work than Tiida in many details.
When Tiida’s battery capacity is 45A, the surrounding protection layer of battery is thin.
When Golf’s battery capacity is 60A, the surrounding protection layer of batter seems slightly thicker and heavier.
For example, in the engine compartment, Golf’s battery is set in a particular protective box and covered by a thick and heavy cap. Around Tiida’s battery is a simple structured fencing composed of white cheap plastic membrane without cover protection.
Tiida’s battery top is bared while Golf’s battery top has a protective cover.
Moreover, Golf has designed the wiring trough for the internal wiring of A column to protect the wiring. Tiida’s wiring is freely laid out in A column, which may lead to noise generation and wire wear.
Sectional conclusion: It is not enough for a car to just have a beautiful appearance and the places not seen by consumers should also be bettered.
In the 1st period of Chaichefang event, Cruze and Civic had their own advantages and disadvantages and they were basically in a parallel pattern. In the 2nd period of Chaichefang event, evidently, Golf has more advantages than Tiida, which was not thought of before the event. To be fair, Tiida has some advantages that Golf does not have, such as 1. a longer wheel base giving a wider leg space for passengers on the back seats; 2. low oil consumption; 3. light driving sense giving a driving comfort; 4. stable quality and low fault rate. However, after removing the interior decorative panels looking well, another kind of sight was found. Why ?
In fact, the cause is very simple—— there is a great difference in car manufacturing concepts and cultural backgrounds, which has led to the difference between Tiida and Golf. From a micro view, since Piech, technology foremost concept has occupied an absolute predominance in Volkswagen Motor Company. From a macro view, German society ‘s custom of worshiping science and technology is incomparable. Supported by this thought, it is no wonder that car models led by technology have been borne one after anther from the soil of this culture. Things will develop in the opposite direction when they become extreme. Excessive pursuit for technology will, of course, lead to cost increase and reliability decrease.
Contrary to German people who see cars as technological products, Japanese people have always understood cars as commodities. A car part that can be made of two components will never be made by three components. The simpler structure means a lower fault rate, lower cost and higher market vitality. Tiida is just the representative of this thought.
Golf has achieved better results in this deconstruction and test event. But it should also been seen that, though Golf has a first-rate manipulation and excellent driving sense in spite of its smaller wheel base, the leg space for the back seats is inferior. Therefore, Golf is more suitable for a 2-3 member family and its market suitability scope is not so wide as Tiida’s. However, this regret can not be changed as a longer wheel base means the loss of partial manipulation, which is a thing with the loss outweighing the gain. Let it keep as it is and let Golf always be a model favored by young people.
Buying Index of Deconstruction
Volkswagen Golf of the 6th generation
Dongfeng-Nissan New Tiida
But, the production capacity cannot keep its present state. Please increase the capacity so as not to let friends loving Golf wait in a long queue for pickup.
About Chaichefang, chexun.com——Based on the concept of building a “most trustful automobile website”, chexun.com established Chaichefang Column, which is issued per month, with an aim to help consumers “be sharp-sighted in buying cars and be clear in using cars”. For this, chexun.com buys cars fully at its own expense and operates independently, endeavoring to make an all-dimensional perspective analysis of commodity cars nearest to consumer actual demand and let consumers see the interior quality of hot-selling models in a direct viewing way.