oil weight recommendation for a '95 Cobra mustang.

[Cobraman1024]

My '95 Cobra mustang has 201,000 miles on it. Original shortblock, ported OEM intake and heads. I basically use this car as a daily driver for work and sometimes do autocross racing and more frequently, drag racing. The heads were rebuilt about 30,000 miles ago with new seals and a valve job so there is no oil burning through the heads. When the heads were off at 160k miles, the cross hatches were still very visible on the cylinder walls. I've religiously changed the oil every 3000 miles with Castrol GTX 10w30 oil and either a Motorcraft FL-1A filter or the PH8a Fram filter.
It was suggested that because of the high mileage, I should start using 20w50 instead of the usual 10w30.

 

[sangyup81]

20w50 is two steps over the 10w30. 10w40 or 15w40 should be more than enough

 

[Nick R]

Stick with 10W-30. You can keep using Castrol GTX if you like. You could also look at Pennzoil YB, or Havoline DS, both of which are also great conventionals. But keep the 10W-30, no reason to go to anything thicker.

 

[JHZR2]

+1 no need to go thicker if there is no observed issues. If you all of a sudden got big consumption or something, it may be different.

I'd probably look at PYB or rotella 10w-30, or even a syn, but your current choice is fine.

If you do see some wet seals, etc., you could try a HM variety.

 

[Cobraman1024]

It was suggested that I use the 20w50 so that the worn engine parts might be sealed better by the thicker oil resulting in better fuel economy. I'm not so sure that a change in oil weight will even matter so thats why I'm here to ask you guys. I was actually due for an oil change today but pending the responses to this thread, I'm holding off. I checked the level on the dipstick and barely any oil was used in the last 3000 miles, if any at all. The color is a nice translucent tan, not black.

 

[Ben99GT]

You absolutely do not need a 50-weight. If you feel the need to step up the viscosity, try a 5W-40 or 10W-40.

 

[mechanicx]

Quote:
and sometimes do autocross racing and more frequently, drag racing


This is the only thing I'd play it cuatious with. If you are going to do a lot of racing in hot weather you might want to consider a synthetic 10W30 or maybe an HD oil like Rotella 5W40 or a 15W40.

 

[OilBlazer93]

Originally Posted By: Cobraman1024
My '95 Cobra mustang has 201,000 miles on it. Original shortblock, ported OEM intake and heads. I basically use this car as a daily driver for work and sometimes do autocross racing and more frequently, drag racing. The heads were rebuilt about 30,000 miles ago with new seals and a valve job so there is no oil burning through the heads. When the heads were off at 160k miles, the cross hatches were still very visible on the cylinder walls. I've religiously changed the oil every 3000 miles with Castrol GTX 10w30 oil and either a Motorcraft FL-1A filter or the PH8a Fram filter.
It was suggested that because of the high mileage, I should start using 20w50 instead of the usual 10w30.


Ahh, 20W-50. I love it. But, there is something my old Mechanic used to say...

10W-30 is fine. 20-Poinn Spread. .Beautiful thing.
If the engine STARTS to get Worn.. Use 10W-40.
If it REALLY Starts to get worn, and maintaining Oil Pressure becomes an issue.. 20W-50.

Unless, of course.. your car SAYS to use 20W-50. And Some Do!

And FWIW: The State Police have -MANY- Crown Victorias. They also have a nice little arsenal of 5.0 Mustangs (4.949L = 5.0,) Camaros, and now, Chargers. Even if its a "Kerry Brown" Supercharged Crown Vic (FAST CAR, though Caprice "Police Interceptor" is also NO JOKE,) .. Im willing to bet 20W-50 gets in there "Special Units."

 

[OVERKILL]

It's a 302. If 10w30 has been working for you.... No real need to change.

BTW, most of them still have visible crosshatching. Both of mine do too.

What do you have for oil pressure? (with a mechanical gauge)

That's about the only way you are going to be able to gauge if you have "worn" parts. Which, with a roller valvetrain, short stroke, tall pistons and low-tension rings, really will be your only clue as to the overall health of the engine.

I'm with Ben. If you DO feel the need to "step it up a notch", then a 5w40 will serve you well.

 

[Cobraman1024]

10w30 is what is recommended by the book.
no problems maintaining oil pressure; I've actually got a Melling high volume oil pump in there and the only time I've seen the oil pressure switch/gauge twitch is because of a bad electrical ground............

 

[Cobraman1024]

Appreciate the quick responses guys, looks like I'll be sticking with the Castrol 10w30 for the next 200,000 miles

 

[OilBlazer93]

Originally Posted By: Cobraman1024
10w30 is what is recommended by the book.
no problems maintaining oil pressure; I've actually got a Melling high volume oil pump in there and the only time I've seen the oil pressure switch/gauge twitch is because of a bad electrical ground............


10w-30 should be fine. Really.

Most people dont NEED 20W-50.

VR1 IS a fine oil, though.

What are your Track times like with that thing? Im guessing... mid-13s? at around... 110?

 

[OVERKILL]

Originally Posted By: Cobraman1024
10w30 is what is recommended by the book.
no problems maintaining oil pressure; I've actually got a Melling high volume oil pump in there and the only time I've seen the oil pressure switch/gauge twitch is because of a bad electrical ground............


The factory Ford gauges are garbage (trust me), to know what you ACTUALLY have for oil pressure, you want something like an Autometer mechanical gauge.

Also, why the HV pump? Really unnecessary on a stock-clearanced 302, and just steals power and is hard on the distributor drive gear.

 

[mechtech2]

The one thing that concerns me is track time.
Oils temps are the key factor. If you get her hot enough, the normal [for 99%] driving oil may be too thin.
Going up a grade could be smart if she gets real hot.

 

[Boss302fan]

Either stay with a good 10W30 or jump up to Rotella syn 5W40. If it was my car and I planned on driving it hard everyday, I would go to a 5W40 weight oil. Mobil 1 0W40 is a great oil and would also work great in your application.

Just noticed that u are in FL and I would use the Mobil 1 0W40 oil. Even when new, I knew guys that used 40 weight oils in cars like yours. .

 

[addyguy]

If GTX got you to 200k miles, why change and tempt fate?

 

[aquariuscsm]

Is it supercharged? How about a synthetic 20W50 (Royal Purple) or a synthetic 5W50 (Pennzoil Platinum)?

 

[Boss302fan]

If u currently use 10W30 then stay with it or do like I said and try Mobil 1 0W-40. It is a really good oil and would work great in your climate.

Stay away from the 50 weight oils until you at least try a 40 weight first.

 

[mustang]

Maxlife 10w30 and an FL-1A would be a very good combo....thats what i use on my 95 GT.

 

[f2racer]

Originally Posted By: addyguy
If GTX got you to 200k miles, why change and tempt fate?


If you don't intend to go longer between oil changes, I'd agree stay with what's gotten you this far...

BTW, do you have iron or aluminum heads on your 302? I had a 94 GT that I installed aluminum GT-40 heads, Cobra intake manifold, and Borla catback on. I miss that car...