"I don't disagree at all with your philosophy, but I'm not sure you've drawn the correct analogy. The OEM battery weighs 50lbs., the Braille/Deka 15 or 21 lbs. So you're looking at a difference of 35/29lbs., not 50lbs."
Sorry, I was unclear on the 50 lb thing. The spare tire weighs about 29 lbs, so removing it and replacing the battery is where I came up with that number.
"Adding the 50lb. pet food bag (with an OEM battery) would equal OEM Curb Weight + 50, the car and it's suspension was not designed for this, so an adverse effect on handling would not be surprising. And, not at all the same as Curb Weight (-) 35 or 29lbs."
I was also concerned about the difference in weight in the front of the car. But I also lost 30-40 lbs in the rear with the flywheel and exhaust. I also had the car's suspension dialed into the new weight as best as possible when I installed Bilstein coilovers. All I noticed is the car is quite responsive and seems to have good balance.
"Also, if you subtract many lbs. overall, you eed to look at your tire pressures because you've changed the maximum load. If you don't address this, you're driving on over inflated tires."
Good point, I continue to play with tire pressures. I tend to run higher pressures when I am using the wheelset with Michellins on them. I have been running those higher pressures with my winter Falken tires (to try to get rid of sidewall flex) and am seeing more wear in the center of the tire.
Ed
Hybrid Mode
