Battery question
 

Good morning all.

I have a 2009 Rx8 R3 with the original battery installed from the dealer when built. With spring around the corner I was looking to put a new AGM battery especially since it's now 8 or more years old. It still starts but getting slow and I'm afraid of flooding. My question is what group size should be in there? Currently there's a group 24 from factory but part lists say group 35 which has left me a little confused. Other forum posts here say 35 for better air flow. Dealer says if 24 is installed to replace with a 24. Any thought or help on the matter is greatly appreciated.

Also was wondering if ngk wires from 04 to 08 is OK to use on series 2?

Thanks all

Either group size works. I use a 24F in mine, because it is the same size as my Tacoma's battery. I have not looked up the dimensions on a 35 to check this, but make sure it is not too tall, if you want to use the battery cover.

Keep in mind that heat kills batteries rather quickly in these cars, so choose a battery that is as heat tolerant as possible. I killed 2 Optimas in 2 years, for example. I am just running a Napa 24F lead acid battery now, after one of those red tops left me stranded 1 mile from a Napa store.

The plug wires are interchangeable.

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I have a 35 in mine, just replaced it again. It does seem to eat batteries every 2 years or so. I've been using just a regular lead/acid battery.

Bosch 35-640B
 

Very highly rated by Consumer Reports. My 8 sits for weeks at a time and fires up strongly each and every time. Lasts for years.

Available at Pep Boys.

Good morning and thanks for the replies. I ended up getting the group 24 agm from Canadian tire. Comes with 5 year free replacement warranty so I figured why not. It was also on sale and only $25 more compared to the flooded lead acid equivalent. And I can keep the cover on. Good to know about the plug wires too... thanks Steve. They are $50 cheaper than the ones from dealer. Not sure why NGK doesn't offer any for 09 and up.

Cheers