I doubt anyone has ever asked an R8 owner, "Why didn't you buy a M5? It has a bigger trunk." But I get the impression a lot of people will ask i8 owners, "Why didn't you buy a Tesla Model S? It has a bigger all-electric range"
...which not only misses the point of both cars but ignores how objectively different they are.
Let's break it down
- 3274 lbs
- 2-door coupe
- 98 kW Electric motor driving the front wheels, 1.5-liter 3-cylinder + undisclosed kW electric driving the rear
- Carbon fiber passenger cell and body panels sitting on aluminum chassis
- 7.1 kW battery pack
- 23 mile all-electric range
Tesla Model S
- 4647 lbs
- 5-door lift-back sedan
- 310kW Electric motor driving the rear wheels
- Aluminum body, chassis, body panels
- 60-85kW battery pack
- 208-310 all-electric mile range (depending on model and source of testing)
So the only objective things they have in common (besides 4-wheels, windows, etc) are (drastically different) electric motors/battery packs and an aluminum chassis. One is a 2 passenger, 2 kid coupe. One is a 5 passenger, 2 kid sedan. One you can drive 300 miles and refuel in 5 minutes, the other requires anywhere from a little less than an hour (at a Tesla Supercharger) to 60 hours (if you use a wall socket) to "refuel." For the record, you can completely discharge the i8's battery and the system will recharge the battery in a few minutes in hybrid mode.
So not only are they objectively different, they have very different "philosophies of use." The Tesla is a great, sporty family commuter sedan. The i8 is a low and wide sports coupe with a Jekyll and Hyde split personality that is apparently great in both roles.
I "get" the need to compare things. People like comparisons, it helps them contextualize something unknown or abstract. They are especially useful with new or expensive cars that only the press and owners will likely experience.
Now then, what DO we compare the i8 to?
- 3700 lbs
- 2-door coupe
- 93kW Electric motor driving the front wheels, 4.6L V-8 + 115kW electric driving the rear
- Carbon fiber monocoque chassis and body
- 6.8kW battery pack
- 18 mile all-electric range
It is the closest objectively comparable car excluding the price and gas engine size. It costs more than 6x as much and has a 3x displacement V-8 instead of a 1.5L I-3. Similar all electric range, similar battery pack, similar front motors, exact same engine layout, AWD, carbon passenger cells, 2-doors, etc. None of which is comparable to the Model S.
I get where the attempt to compare comes from. There are very subjective criteria you can use to make a comparison between the i8 and Model S. Both appeal to bleeding edge tech buyers and early adopters. Both "make a statement" for people that care about that aspect of car choice. Both will sell to coastal Californians like crazy. Both project an "eco" image.
There are a few articles I've read that correctly choose to make a comparison between the 918 and i8 rather than a Tesla (Lieberman at Motor Trend said he liked the BMW more), but they are rare.
Let's put it this way:
I imagine explaining what a zebra looks like to someone that's never seen one is hard. But if I attempted to compare it to something else, I would point towards a horse before pointing to a elephant.