OPTIMA Batteries High Performance D34/78 YellowTop Dual Purpose Sealed AGM Car, Truck and SUV Battery, 750 CCA, Dual Terminal, Maintenance Free, Versitile Mounting

Fit just fine in my 2000 mustang GT battery holder. No modification needed. No clearance issues etc. I should have bought years ago.The one I got is: Optima Batteries 8014-045 D34/78 YellowTop Dual Purpose BatteryThe battery was about 1mm longer than the tray (from front to rear of car vs left to right), but the tray just stretches out to accommodate. I laughed and said to myself - "Are you serious?!? that's what I was all worried about?!? Lol!" "Good grief - this fit just fine!!! Lol" :-)1st pic shows Mustang2nd pic is looking at battery from drivers side - it shows how the tray stretches to accommodate the 1mm increase in size3rd shows from the drivers side looking at the front of the battery in the mustang - the thing to notice is that the front side didn't need to stretch since it's already stretched on the back side4th pic shows mustang from the front and how it's installed without the blue adapter, without the large yellow tray adapter, and without the larger of the 2 red adapters (I left them on top to show how they're not used)5th picture is from the drivers side looking over the battery to show how I used the red clip that came with the Optima. This red clip is the same as the stock black clip. But the new one looks nicer.6th picture is from the front at headlight level - they show how I didn't run into any clearance issues.7th shows no clearance issue.The pictures help.See, the Optima site doesn't list it as fitting in the 2000 mustang GT. But yet we all know people put them in their mustangs... So the discrepancy between the 2 kept me from buying for a long time.But all you do is drop it in, and lock it down. In hindsight, it was really no different than any other battery I have ever installed.I used the new clamp that came with the battery vs the factory because because the new one was clean, red, and looked cool, but it was identical in shape to the factory clamp.There were a few other clamp items (blue tray items) for applications in other vehicle types, and they caught me off guard and so I tried to use all of them - partly because I thought they looked cool, but most because I didn't realize that they're actually for different vehicles; it ended up just being the red one, which was the same as the factory black clip that came with the mustang. The other ones would raise the battery with no benefit. I don't remember if there were any clearance issues if it was raised, but don't bother with them unless you're just having fun with the battery changing project and just want to see. You might save them in case you ever get a new car and want to bring the battery - Optima batteries are notorious for lasting a super long time.But yeah - the yellow top Optima fit just fine in 2000 mustang GT.I was all worried that I was going to need to get an F150 tray from a salvage yard (which was a pretty neat idea that someone had done successfully), or order a new cool fancy tray (but those aren't cheap). Neither are necessary, but they're good to know because the knowledge helps guarantee that can somehow fit if your experience is somehow different than mine. But you won't need to do it.You can still do stuff like that it you want, but do it after you put your battery in - because if your tray is the hard plastic one like mine, there is absolutely no problem putting it in. No modification to your tray is needed.I was very happy about how easily it went in.Can't believe I waffled for years over getting one.The low price on Amazon helped too. The absolute best battery I could get otherwise was around 120 dollars, but not nearly the same quality as the Optima. The Optima red top wasn't much more than that on Amazon, but I went yellow because it is an even better battery.Both the red and yellow are great though - WAAAAY better than other batteries. But most people know that about Optima batteries. I don't think they need people to endorse them.I'm writing this not so much because of Optima's quality (already known), but more so 2000 Mustang owners know that they can get this and be happy.It should be the same for any 99-04 mustang, the red or yellow top. But my knowledge is first hand for the 2000, and the Optima Yellow top Optima Battery that I'm rating: Optima Batteries 8014-045 D34/78 Yellow Top Dual Purpose Battery

Optima makes the best batteries that I have ever used. Note in the photo the manufactured date of 4/16, of the original battery. It has lasted nine years in my FJ Cruiser (battery cable mods required). It still holds a charge, but the voltage drops after a couple of days if the car is not run. I won’t pay $200 for a battery with an expected life of 2-3 years. The higher cost of Optima batteries is a bargain.

Awesome battery and it works so well in my SuperDuty to run all my accessories and sound system.

CAUTION, You may want to consider risk of buying an Optima battery, BUT DEFINITELY DO NOT BUY ONLINE OR VIA AMAZON. I have used Optima Y-Top batteries on ALL of my cars/trucks since they first came out. I generally got 5 to 6 years life even hot in South Florida (Miami to Stuart). I never had a warranty issue. I found them to be very robust batteries even if you did something stupid like leaving lights or a load on. When they finally degraded, the after charge standing voltage would gradually drop indicating it was time to replace. Even in a degraded condition, they would easily recharge or jump start well enough to allow time to get a new battery. So I finally trusted this brand enough to buy from Amazon, & NOW IT LOOKS LIKE I GOT SCREWED for a $330 battery. Battery was fine on 11/20/24. On 11/22/24, my new Yellow top 34/78 battery failed 15 months after it shipped from Amazon & 9 months after I installed it. Voltage suddenly dropped to an unrecoverable 8V or less. I had read some bad reviews on Corvette forums, but discounted them based on my prior experience. I bought in August 2023, but delayed the install as the old degraded Y-Top (Year 2018 date code) was still able to run reliably in my truck. On 11/24/24, I contacted the seller for a warranty claim via Amazon link on 11/25/24. After 6 days, I have received absolutely no response (crickets). Now that I review the warranty requirements, I see that you are required to ship the battery back to the seller. For a non-business personal ship, UPS would charge well over $100 for a 44lb battery! If my valid warranty claim is resolved fairly, then I will revise this notice. HOWEVER, BASED ON HOME I HAVE BEEN IGNORED FOR A FULL WEEK, DO NOT BUY OPTIMA BATTERIES ON AMAZON.

Shipping Box flimsy. Should be shipped in stronger reinforced box. One 'ding' in plastic battery casing.Battery works great. My last onevlasted (in Las Vegas) for 10 years.

My son appreciated this present for his truck, and so far this battery works very good.

Battery developed an issue approx 21 months after purchase, Contacted Optima Customer Support via email, new batrtery received in 4 days!!!Can't ask for any better Service!Thank you very much!!

Old optima batteries seemed to last longer, hold a charge longer, etc. these new ones cost more than oem/cheap local parts store brand batteries and don't even last as long.. definitely don't hold a charge as long. i have to keep a charger on my yellow top in my classic car and the last one died after about 3yrs. old optimas would last 5+ easily.