Tag Archives: BMW i3

Tearing Down Tesla Segment 2: Tesla Model 3 vs. BMW i3 with REx System

What costs more? An electric vehicle with an extended range system or a full electric vehicle? How does OEM assembly time factor in?

Background: The supplier component costs for a full battery electric vehicle, like the Tesla Model 3, are often more expensive than an electric vehicle with a range extender, like the BMW i3. However, for the OEM, an electric vehicle with a range extender (or any type of hybrid vehicle) will drive more OEM assembly costs. Additional assembly workstations are required to build a range extender system (often in a spur line), then more stations must be added to the main final assembly line in the vehicle assembly plant.

Side note: this does not include the cost to assemble the engine, which could be supplier or OEM assembly costs.

Data: The BMW i3 REx system can be estimated to drive approximately $45.61 in OEM assembly costs for installation and assembly of the system components into the REx module. This drives the need for approximately 35-40 more workstations in the assembly plant.

Methodology: Munro’s Design Profit® software has a built-in scoring system that allows users to analyze handling and interaction times when assembling parts. Munro uses this scoring system, along with a library of industry standard fastening and operation times, to generate an estimated time and motion study for the assembled parts and work cells that are required. Then, in order to generate assembly costs, that assembly time is matched with a work cell rate for the require operator and equipment.

Tearing Down Tesla: Comparing Secrets of Tesla and Other Leading EVs

Calling all automotive engineers looking for objective technical information about today’s leading electric vehicles (EVs).

This post kicks off a series of articles that will compare notable aspects of leading EVs. From OEM assembly time to suspension and from battery cooling systems to HVAC ducting and venting, this series will cover a lot of ground. Most importantly, it aims to offer knowledge that’s interesting and valuable to today’s engineers … with data points that support our findings.

We used our proprietary Design Profit software for all of our teardown analysis. It enables the teardown team to document each part, how it is installed in the vehicle, as well as how it’s assembled in each subassembly. With this data, we’re able to reverse engineer the assembly process for the given vehicle. More information about the software can be found here: https://designprofit.com/

With that said, here’s the first post ….

Did you know that the BMW i3 has a serviceable battery pack while the Tesla Model 3 doesn’t?

Background: The BMW i3 has a serviceable battery that can be lowered from the vehicle by removing the pack’s mount bolts located on the exterior of vehicle. Individual sub-packs can be replaced after removal of the cover and sub-pack fasteners.

The Tesla Model 3 battery pack was designed not to be serviced. It requires the removal of bolts in the interior and exterior of the vehicle to drop out the battery pack, as well as the removal of the vehicle’s seats and carpeting (to access bolts). The battery pack uses structural adhesives to seal and mount its cover and sub-packs, which does not allow service to open and easily remove modules for repair.

Insight: The advantage of the Tesla Model 3 non-serviceable battery pack is that it reduces the final assembly cost of the battery pack. The disadvantage is that if significant cell damage happens in the pack, then it requires a full swap of the battery pack.

Side note: based on the range for the Tesla Model 3 battery pack vs the BMW i3, in order to equalize, the BMW i3 assembly costs would be considerably higher than the current cost analysis.

Data:  The Tesla Model 3 uses three lines of structure adhesive bead and 78 fasteners, with a final assembly cost of $36.87 to mount the sub-packs and install the battery pack cover. The BMW i3 battery pack uses 120 fasteners, with a final assembly cost of $41.39.

Sandy Munro Shares Thoughts on Structural Adhesives in Automotive Engineering Article

In the recent Automotive Engineering article “Stuck on Structural Adhesives” from Automotive Engineering, Munro & Associates CEO Sandy Munro shares “We’ve used adhesives forever. It’s just that the amount of confidence in them has drastically changed [in recent years].”

According to the article, as the need for lighter materials and enhanced body performance intensifies, structural adhesives are flourishing as a materials-joining solution. The widening reliance on high- and ultrahigh-strength steels and aluminum for body structures, particularly unitized bodies-in-white (BIW), to cut weight without sacrificing crash-mitigating strength or handling degrading rigidity, is the prime factor driving the expanding use of structural adhesives.

Sandy references his firm’s findings from the BMW i3 teardown and adds, “Anything you can possibly imagine, they glued together. The polyurethanes they are using are unreal.”

To read the full article, visit: http://bit.ly/2pHYsRS.

Unlocking the Secrets Of BMW’s Car Of The Future

Joann Muller of Forbes fame recently visited Munro & Associates with her camera crew for an exclusive tour of the BMW i3 teardown and reverse engineering project.  For the last several months the team at Munro have slaved away tearing down and analyzing this high-tech vehicle, uncovering one new technology after another.

Joann describes the scene as, “…a nondescript industrial building in suburban Detroit, (where) a $50,000 BMW is lying in pieces. The place looks like an illegal chop shop, where stolen vehicles are disassembled to be sold as parts.”  Muller goes on to explain though, “But A. Sandy Munro is no car thief: he paid full price for the BMW i3 he subsequently tore apart. Nor is he selling it for parts. He is, however, selling information about this remarkable car to anyone who is interested. And rest assured, a lot of people in the auto industry want to know its secrets.”

Amongst many of the new technologies and process uncovered in this teardown, Muller emphasized the overall importance of these breakthroughs, “to cope with a confluence of troubling trends — global congestion, pollution and, yes, high fuel costs — that threaten the long-term viability of the automotive industry.”

To see the video and article click here.

Or to download the BMW i3 Report Prospectus click here.

The Future of Cars Looks Very Different

The last few months have seen a flurry of activity at Munro & Associates as the team has been undertaking the massive task of dismantling, recording, and analyzing the BMW i3 in minutia for one of the largest and most comprehensive teardown benchmarking and reverse engineering studies the company has ever seen.  This has attracted a lot of media attention, including from the prestigious Wall Street Journal.  Journalist Joseph B. White was one of the visitors who got the full tour of what innovations and secrets this breakthrough vehicle holds.

“Seeing the battery-powered i3 in pieces puts into perspective how far this industry has come over the past quarter century…” , remarks Joseph White in his article.  “The i3 combines some of the auto industry’s oldest ideas with some of its newest”, White reminisces, impressed with the idea of the classic “body-on-frame” concept adapted using the latest carbon fiber technology to achieve a lightweight yet strong structure that is leading the industry.  “BMW’s carbon-fiber city car is an important marker for anyone trying to figure out the future of an industry that is still a centerpiece of the global economy after more than a century.”

White describes Munro as a place where the team “…takes apart cars, seeking clues to design and manufacturing tricks he can sell to manufacturers eager for a cram course on their competition.”

Click here for a link to the original article.

Or to download the BMW i3 Report Prospectus click here.