Duralast 49-DL or Interstate MTP-93
A little background before the question. I have an 02 M3 and an 03 540. The m3 is on it's original battery, and the 540's Interstate MTP-93 just died. So really I needed 2 batteries. I went to Autozone and picked up and installed a DL-49 in the 540i. Just for fun I decided to see if Interstate would warranty the battery that died. TUrns out, they gave me a new battery for $57, so I took it considering a new one is $157.
I was thinking it would fit in my m3, and it might...but Interstate says that the "correct" battery is $185 and only has 640cca. The $57 MTP-93 has 850cca.
Unfortunately I can't return it even though it is still wrapped in celophane. The questions are:
1) Will the MTP-93 fit and work in the m3?
2) Why would someone pay $185 for a battery that has worse specs than the $157 one?
3) Should I put the 49-DL in the m3 and the Interstate in the 540?
4) I have a battery tender. If I hook it up to the engine bay and THEN remove the battery will that save my codes?
Last edited by grocery_grabber; 01-17-2010 at 12:26 PM.
Reason: omit info