New battery Purchase
 

I am going to buy a new Interstate battery. The Interstate websight shows a MTP-93 as the battery for a 928. Doing a search on here, I found several comments about the MTP-91 being the proper fitting battery and the MTP-93 as being to large.

Can anyone confirm the MTP-93 fits a 1983 before I purchase the wrong size battery??

There are only 3 or 4 actual battery manufacturers in the US. Everybody sources their batteries from these 3 or 4(including Interstate). I believe that a group size 48 is the correct size for your 83. From the Interstate website, I can't tell what group the part number you posted is in.
I recommend you buy a group 48 battery that offer the highest CCA available at the lowest cost. Battery warranties , I have found, are generally non-transferable. Therefore, I bought my last several batteries from Walmart because I know that no matter where I am, if I do happen to have a battery problem, I can get it warranteed at the local Walmart.
Good Luck.

I figured it out.

The MPT-91 is a battery designed for the newer 928 with the smaller battery box. The MPT-93 is 3in. longer, and designed for the early 928 with the longer battery box. The smaller battery box was designed to make additional room for the dual exhaust of the later models..

Try the Bosch battery from Pep Boys, it has a 3 year free replacement warranty and is only $119 bills

Johnson Controls makes about 90% of the batteries sold in the USA, Interstate is the best battery that Johnson makes.

Negative. Optima is their best battery.:icon107:

If you say so.

I'm with you. I think I paid ~$80 at WalMart. It was the big one--for the '84, but I think they had both sizes.

Another recommendation for the WalMart battery. 3 year replacement warranty (not prorated) and around $70+ for the group 48 size here in the Phoenix area. Best deal I found.

My first two didn't last a year, third one I can't seem to kill.

Rest of my batteries are DuraLast Gold, Autozone, all holding up well and I am not kind to batteries. They never seem to go on sale though, and kind of irks me to pay full price, so I am open to Walmart batteries if they hold up and warranty terms are better than 3 year non prorated replacement.

I recently bought an 84 month warranty battery from NAPA for ~$110 (for an '89 S4). The 72 month warranty was a few bucks less than $100. Both made by DEKA.

Gary Knox

I just replaced my second Duralast in 4 years with a Bosch, $109 in my neck of the woods. Either I have an alternator issue or the Duralast is a faker. Both of them gave it up at 2 years showing 12.5 volts and having always been either disconnected or on a trickle charger. The last one was especially devious as I had just returned from a 40 mile trip, pulled in garage, tried to start and the dash went dark. I am going to get the alternator checked, but at this point I am going with Bosch.