Originally Posted by Kostamojen
We've seen a wide range in curb weights lately from both magazine articles and leaked information.
My goal with this thread is discuss why we are seeing such a wide range in weights this close to the actual debut of the car and why we are seeing the numbers we are seeing.
One important thing to realize about this car is that its a Subaru drivetrain chassis for the most part. The suspension bits are almost straight out of the current Impreza's, and the drivetrain minus the front differential and axles is going to be close to the same weight of a Subaru drivetrain.
Why does this matter? Because it gives us a good indicator of how much this car will actually weight.
Curb weights and Subaru's:
I know a few folks here know me from other Subaru forums, but one of things I've done over the years was compile a list of Subaru curb weights for EVERY model sold in the U.S. These numbers were taken from actual service manuals so they were about as accurate as they can get.
The lightest AWD Impreza ever sold in the U.S. was the 1993 base model L and that came in at 2500lbs. This was a car that had 14" wheels, NO abs, NO passenger airbag, NO power anything, TINY brakes with drum rear brakes, possibly NO A/C (not sure) and NO options at all possibly not even a stereo (I don't have the exact model details, I need a brochure for that).
The lightest model gained weight in 95 up to 2555lbs and in 1996 several reinforcments were added to the chassis along with other component improvements that upped the weight to 2715lbs!
Now I also have some European weights, but since they measure curb weights different it is impossible to know if these compare correctly. But in 1993, the lightest AWD model in Europe was 2460lbs but had a smaller motor and probably even less options, and I'm not sure where that number came from, possibly not even service manuals.
Important things to note:
The EJ engines form this period were SOHC 1.8 or 2.2 motors with MUCH smaller heads (Phase I) and the engine was lighter than later 2.5 SOHC and DOHC motors.
PLUS, the rear subframe on these cars was VERY light compared to the Multi-link subframe in the current cars. How do I know this? Well I worked in a Subaru parts department for awhile and had to carry these things around! The multilink subframe is VERY heavy, not including the actual multilink components. Probably 50-75% heavier than the non-multilink subframes. The strut assembly is heavier on the non-multilink rears, but not nearly enough to compensate for the subframe and component weight difference.
Comparing to the FT86 chassis:
Now I know you might be saying to yourself, "Why are we comparing an AWD car to a RWD car in terms of weight?". Well the important thing to know is that Subaru's AWD is simple and mechanical. If you remove the front axles and front differential, you have a RWD drivetrain. That accounts for ONLY 50lbs or so no more. Yes, there is a center differential but Subaru 5-speed manuals are NOT complicated and not heavy and compared to the 6-speed in the FT86 it will be very comparable on weight probably including the middle AND front differential!
Now, how does this matter with the FT86 chassis? Well, we know several things about the FT86 chassis now and what the car will have that will give us an indication of the weight of the vehicle.
First, the rear subframe is the same as the current Imprezas. This means the rear suspension is heavier than earlier Imprezas. The front suspension and subframe is an unknown, possibly lighter but supposedly the same engine mount style so probably close to the same.
Second, the FT86 engine is heavier. The FB motors gained a little weight over the SOHC EJ25 normally asperated motors due to the use of the timing chain, DOHC and aluminum timing chain cover. Even with the plastic manifold, they are heavier. And the SOHC EJ25's were heavier than earlier Impreza Phase I motors.
Thirdly, the FT86 has much larger brakes and wheels than early Imprezas. This will add to the weight even more.
Fourthly, the FT86 WILL have between 4 and 7 airbags possibly more. Thats extra weight right there. Even if the radio is optional, the bits and pieces from the FT86 WILL weight more than early Imprezas.
Finally, the Chassis... First generation Imprezas were small, very small. The chassis were also developed 20 years ago so they don't have the safety considerations in mind as a current car would have and also don't have the structural rigidity either. Even if they managed to save weight on the FT86, its still going to have as heavy or heavier chassis than a first generation Impreza.
Doing the Math:
For the purposes of this segment, I'm going to use my 1995 Impreza because its a known quantity (I know what came with the car and what didn't) and I know the curb weight... 1995 L Coupe AWD - 2605lbs (has A/C, small 14" wheels, no ABS or power anything)
Here are a list of the things I discussed and how they compare between the older Impreza and the new FT86-
Engine - FT86 heavier by ~10-25lbs
Transmission - AWD probably heavier, but not much, subtract 50lbs (+10 for 6-speed vs. 5-speed)
Front Suspension and Subframe - Probably a wash
Rear suspension - FT86 ~25lbs heavier
Wheels and tires- FT86 10-20lbs more per wheel, ~40-80lbs
Brakes - FT86 5-10lbs heavier each corner, ~20-40lbs
ABS - FT86 has it, add ~20-30lbs
Airbags - Impreza has 2 vs. 4+ for FT86, add 10-30lbs
Interior - Probably a wash (the rear seat only weighs 30lbs on the Impreza and the front seats are not that heavy, the rest of the interior is spartan including bits in the trunk)
Chassis - Unknown, close to wash. Impreza has almost zero extra reinforcements
Total: FT86 heavier by between ~50 and 230lbs
So the FT86 might weight between 2650lbs and 2800lbs+
The bad news:
This does line up almost exactly with what we saw from the Toyota leaked brochure weight numbers with the higher weights being determined by content, and the VERY low weight being a base model with steel wheels and unpainted bumpers (and no radio).
I highly suspect the final weight is going to be OVER 2700lbs possibly even higher.
The ONLY way this won't happen is if the chassis is insanely light, which there is almost zero chance of it weighing less than a 20 year old tiny chassis with no modern structural improvements.
The GOOD news!:
The good news about this is that weight reduction is EASY for early Imprezas. This will also apply to the FT86 chassis.
There are other threads about this, but the easy weight reductions are these:
Delete the back seat (~30lbs)
Dump the junk in the trunk (~30lbs)
Lightweight battery (~15lbs)
Lightweight bumper beams (~30lbs)
Those are all things I've done with my Impreza for racedays (the bumper beams stay put though) and all things that can easily get the car down to the 2600lbs range or possibly lower if it does turn out that the base models are in the 2600lbs range.
Final thoughts:
There a lot of people who are going to be upset about the production weight of this car. Its not going to be as light as some of the ridiculously light FWD cars on the market right now (Mazda 2 comes to mind).
But this is a RWD car thats not made of exotic lightweight materials and not made 20+ years ago when crash tests and safety standards barely existed.
WE SHOULD BE HAPPY that this car will weigh 2800lbs or less and realize that our expectations of a near 2500lbs car are unwarranted and unrealistic.
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