Is It 5 Or 6 Quarts? 1999 Mustang Gt

A quick backstory..I know the internet is not in agreement on this subject. I have read many conversations on different forums regarding this topic and no one really has really come together on this. The logic is always the same..its the same oil pan and the same motor so it should be the same amount of oil for 99-04.

People often quote a TSB that says Ford changed the spec in 02 and said it applies to all Mustang GTs from 99-04. I have yet to find this TSB. I called Ford and talked to my local dealership service dept. They cannot find any such TSB. They said the spec for that Windsor motor is 5 Quarts. Said the Romeo motors have the 6 Quart requirement. I asked about the OEM dipstick that (Late Model Restorations) LMR.com sells and even gave them the part number. LMR claims its for all Mustang GT 4.6L for 96-04. According to Ford that is for Romeo only and the Windsor disptick is no longer available. You would think this means its been replaced by the Romeo right? The Ford Parts Dept cannot find anywhere in the system where it says the Romeo dipstick is a replacement for the Windsor dipstick. They said its not for the Windsor and suggested I either get a Windsor one from a junk yard or buy an aftermarket one for that motor.

People also quote an independent study that says all the above year 4.6L motors need 6 Quarts due to possible oil starvation under certain circumstances regardless of what the manual says. I cannot find this study either. I can only find people mentioning it.


I sent an email to LMR asking about this TSB that backs up their claim that 6 quarts was indeed recommended by Ford for 96-04. They replied but never provided that TSB. I just have been getting replies saying "it is for those years" and "I had a 99 GT and 6 quarts is what I put in it". If they claim there is a TSB that is giving them the green light to use 6 quarts instead of 5 I'd think they would have it handy. Ford certainly doesnt.

So my questions are these...Does anyone know where this TSB exists? Does anyone have a link to this independent study?

I am not trying to start an oil war here but I'm just trying not to FUBAR my car.

Thank you for being willing to do that. The only thing I can find thats Oil related is where they changed from 5w-30 to 5w-20 and theres one dipstick out there in 2002 that they changed to make the markings more clear to read. There is also a shorter dipstick for the Romeo engines.

I cannot seem to find anything else and my Ford dealership just pretty much says that TSB I asked about doesnt exist. LMR got back to me and said this when I told them Ford says the TSB doesnt exist and asked if they had it on hand since they say theres a TSB for this: "This is only gong to be through Ford, unfortunately we do not have this available. You will always find conflicting info on this matter. Some people say use 5, some say 5.5, some say 6. Every 2V I have ever worked on I always put the 6 back in it to be safe. "

rancorkeeper said:

You're refering to TSB 03-8-3 APR 03 Engine - Oil Level Indicator Markings which states:

"Ensure the vehicle is sitting on level ground. Set the park brake and ensure the transmission selector is in PARK position, or in FIRST gear on manuals. The engine must be OFF. The best time for determining oil level is before the engine is started and the oil has had sufficient drainback time to the sump. If the engine has been running, allow it to sit for a few minutes turned off. An oil drainback period is required before taking an initial reading.

If the level falls below the lower hole, fill with one quart of oil. If one quart is insufficient to raise the level above the mark, add oil until it records within the crosshatch area. Use caution during this procedure as some time is needed for oil to drain down through the drainback passages in the cylinder head, to the oil pan. Adding oil a quart at a time repeatedly without sufficient drainback may overfill the sump.

If the oil level falls between the upper and lower hole do not add more oil. Adding an extra quart could cause overfilling and may result in aeration (foaming) causing eventual damage to vital bearing surfaces and moving parts inside. Overfilling will require some oil to be drained out until the indicator shows the level between the upper and lower holes of the blade. DO NOT expect the engine to “consume” the extra oil back down to the upper oil fill level hole, or consider it as extra lubrication protection for the engine."

Click to expand...

Ty for that info. I read that one earlier but that reads its is only for 2002-2003 Mustang's. It doesnt mention it retroactively applies to all Mustang GT 4.6L from 96-04 like sites such as LMR claim. If this is the TSB that this assumption is being based off of then thats a huge assumption. It doesnt even specify if its for the V8 Mustang. It lists vehicles like Escape and Escort as well which I know doesnt have a V8 option.

The "Refined" image does show it moved up a bit on the stick so I could see a quart being added to make it meet the "max" hole.

Since it doesnt list all the Mustangs from 96-04 like LMR, forum posts, and other sites claim, I am hoping theres another TSB out there that states it.

Then again I could be interpreting it wrong so this is a good place to find that out.

A link to the TSB you mentioned:https://stangshiftergaskets.com/Sit...iles/ENGINE OIL LEVEL INDICATOR MARKINGS .pdf

Sorry it pasted twice. I would just delete it or edit it there but the forum is warning me about possible spam on the edit. Here is the TSB: https://stangshiftergaskets.com/Site/PDF Files/ENGINE OIL LEVEL INDICATOR MARKINGS .pdf

Sketchy_GT said:

Yeah they only relatable tsb is the one changing from 5w20 to 5w30

Click to expand...

I think you mean the other way around. 5w-30 to 5w-20. Im only pointing it out just in case someone comes across this thread in a google search.