2003 Mustang GT oil Change

SCobraVT99 · 01-06-2008, 12:59 PM

On my oil cap it says 5W 20

Can I use 10W 30? What oil should I be using? Or do I need to use 5W 20?

tire · 01-06-2008, 01:03 PM

yes. (and i don't care what others might say)

almost all late model cars use really thin stuff like 5w nowadays. 10 will work fine though!

wait... it says use 5w20? i have been out of the loop for a couple years but i thought it was 5w30?

austin

SCobraVT99 · 01-06-2008, 01:10 PM

it for sure says 5W 20

thatdavidkid · 01-06-2008, 01:16 PM

use 520.... the tollerances on newer cars are MUCH tighter than older cars... i've seen oil pumps burn up and cause catastrophic failure due to using oil that is too thick

thunderchicken · 01-06-2008, 02:42 PM

Also,if you were to use any other weight of oil other than specified by your owners manual,oil cap,or dealer recommendations,it will effect you gas mileage....dramatically aswell......

Aviator Stang · 01-06-2008, 03:16 PM

What I did was use 5w 30.

thatdavidkid · 01-06-2008, 03:29 PM

Quote:

Originally Posted by Aviator Stang

What I did was use 5w 30.

why? were you burning oil? i dont understand ppl that think they're smarter than the engeneers who designed their car... unless you really have a reason, stick with what they tell you... "side molding removed" is not a mod that requires thicker oil..

TheBocSez · 01-06-2008, 04:45 PM

It was always explained to me that Ford and other manufacturers went with thinner weight oils in order to gain additional fuel milage needed to meet standards and that it actually has nothing to do with clearances. Im sure he will be fine with a 10wt oil.

H0SS302 · 01-06-2008, 05:10 PM

Quote:

Originally Posted by thatdavidkid

use 520.... the tollerances on newer cars are MUCH tighter than older cars... i've seen oil pumps burn up and cause catastrophic failure due to using oil that is too thick

im gonna have to agree with the dave... use what the factory calls for. why even tempt something bad, just use what the motor calls for.

**AdRock** · 01-06-2008, 11:45 PM

TheBocSez is right. The tolerances in the new 4.6's compared to the older ones haven't changed. The weight of oil changed so that Ford could get better mileage for the Feds, thazt's it. I run 5w-30 and wouldn't put anything thinner in there. The engine isn't gonna have a problem with the 5w-20 at all if that's what you rather run.

SCobraVT99 · 01-07-2008, 11:32 AM

I put Castrol 10W-30

96greengt · 01-10-2008, 09:32 AM

Quote:

Originally Posted by TheBocSez

It was always explained to me that Ford and other manufacturers went with thinner weight oils in order to gain additional fuel milage needed to meet standards and that it actually has nothing to do with clearances. Im sure he will be fine with a 10wt oil.

That is true, but David is right, the bearing clearances in the 4.6 are extremely tight. The 5W30 is choice, but 5W20 if for better gas mileage.

Here are basic specs on crank clearance 0.00098-0.00197 in

And rod clearance spec 0.0010629-0.0027165 in

So do the math and tell me that a 10W30 oil will pass through with ease.
Yes it will, but it strains going through.

lasersnake96 · 01-12-2008, 12:12 PM

Quote:

Originally Posted by thatdavidkid

use 520.... the tollerances on newer cars are MUCH tighter than older cars... i've seen oil pumps burn up and cause catastrophic failure due to using oil that is too thick

x2, i run 5w20 mobil one in my Lightning and GT with good results

Bigdrumma22 · 01-12-2008, 05:33 PM

I use Mobil 1 Full synthetic 5W-30 simply because it's not new anymore and wasn't when I got it. If bearing tolerance has anything to do with it, mine have grown with mileage. I've got a little over 71k, so I don't see an issue with using a little bit thicker oil unless the car is brand new, or you're breaking in the engine. It's not like he's trying to throw straight 40HD in or something. I haven't had any problems and usually get 19-20 mpg.

TonyToughNuts · 01-12-2008, 11:25 PM

holy crap!! 19-20?? see, use 5-20 like it says on yours (and mine) i get 26 if i'm easy and 21 if i'm tearing around. crap. i get 17 doing 135 mph on I-10 between Ft. Hood and Ft. Bliss! and that is stock minus a CAI and a home P&P TB/plenum.

Bigdrumma22 · 01-12-2008, 11:32 PM

Quote:

Originally Posted by TonyToughNuts

holy crap!! 19-20?? see, use 5-20 like it says on yours (and mine) i get 26 if i'm easy and 21 if i'm tearing around. crap. i get 17 doing 135 mph on I-10 between Ft. Hood and Ft. Bliss! and that is stock minus a CAI and a home P&P TB/plenum.

Well I thought someone might come up with numbers like that. To be more specific, I get 19-20mpg mostly street, lots of traffic, lots of lights in my area. Highway only time I measured I got 23mpg. Mine is stock with cold air, catback, and offroad H. I only have 2 02 sensors also which would effect my air/fuel ratio. There are a number of variables that factor in, tire size, etc. How many miles do you have and what trans? Due to the overwhelming thoughts on this, next oil change, I think I'm going with the 5W-20 to see if there is any significant difference. I doubt there will be, but we'll just have to wait and see.

86sleeper · 01-13-2008, 09:56 AM

i use the non-synthetic 5w30 as that is what my blower likes.

96greengt · 01-13-2008, 10:16 AM

Quote:

Originally Posted by Bigdrumma22

If bearing tolerance has anything to do with it, mine have grown with mileage. I've got a little over 71k, so I don't see an issue with using a little bit thicker oil unless the car is brand new, or you're breaking in the engine. It's not like he's trying to throw straight 40HD in or something. I haven't had any problems and usually get 19-20 mpg.

If you have bearing tolerance that grows with mileage, then your engine has issues.

Bigdrumma22 · 01-13-2008, 10:20 AM

Quote:

Originally Posted by 96greengt

If you have bearing tolerance that grows with mileage, then your engine has issues.

All I mean is engine wear. That is what engines do with accumulated mileage isn't it?? Are you saying no matter how old or how many miles an engine has, you should always you the specified oil?

96greengt · 01-13-2008, 10:21 AM

You must not know a modular then do you?

01-06-2008, 12:59 PM	#1
SCobraVT99 God's gift to Dell Join Date: Mar 2007 Location: Round Rock Posts: 1,202 Trader Rating: (0)	2003 Mustang GT oil Change On my oil cap it says 5W 20 Can I use 10W 30? What oil should I be using? Or do I need to use 5W 20?

01-06-2008, 01:16 PM	#4
thatdavidkid looks mean, workin' on the fast Join Date: Oct 2006 Location: Denton Posts: 3,698 Trader Rating: (0)	use 520.... the tollerances on newer cars are MUCH tighter than older cars... i've seen oil pumps burn up and cause catastrophic failure due to using oil that is too thick __________________ t-5 swap, billit quadrant, upr firewall adjuster, steeda tri-ax, custom jb tool and fab one off subframe connectors. coming soon: 8.8 w/ 3.55:1's, '00 gt brakes, followed by my 306 swap

01-06-2008, 02:42 PM	#5
thunderchicken WOOB WOOB WOOB WOOB NYRRK NYRRK NYRRK NYRRK Join Date: Mar 2007 Location: San Antonio TX. Posts: 1,503 Trader Rating: (0)	Also,if you were to use any other weight of oil other than specified by your owners manual,oil cap,or dealer recommendations,it will effect you gas mileage....dramatically aswell...... __________________

01-06-2008, 03:16 PM	#6
Aviator Stang Registered User Join Date: Jul 2006 Location: Kenedy, TX Posts: 101 Trader Rating: (0)	What I did was use 5w 30. __________________

01-06-2008, 04:45 PM	#8
TheBocSez KEN LEEEEEE tu libu dibu daucoo...... Join Date: Mar 2004 Location: Converse, TX Posts: 1,064 Trader Rating: (1)	It was always explained to me that Ford and other manufacturers went with thinner weight oils in order to gain additional fuel milage needed to meet standards and that it actually has nothing to do with clearances. Im sure he will be fine with a 10wt oil. Last edited by TheBocSez; 01-06-2008 at 10:18 PM.

01-06-2008, 01:03 PM	#2
tire ka-chow! Join Date: Jun 2003 Location: SoCal Posts: 5,745 Trader Rating: (1)	yes. (and i don't care what others might say) almost all late model cars use really thin stuff like 5w nowadays. 10 will work fine though! wait... it says use 5w20? i have been out of the loop for a couple years but i thought it was 5w30? austin

01-06-2008, 01:10 PM	#3
SCobraVT99 God's gift to Dell Join Date: Mar 2007 Location: Round Rock Posts: 1,202 Trader Rating: (0)	it for sure says 5W 20

01-06-2008, 11:45 PM	#10
AdRock I am the Great Cornholio, give me all your TP Join Date: Nov 2003 Location: On The Move Posts: 5,097 Trader Rating: (5)	TheBocSez is right. The tolerances in the new 4.6's compared to the older ones haven't changed. The weight of oil changed so that Ford could get better mileage for the Feds, thazt's it. I run 5w-30 and wouldn't put anything thinner in there. The engine isn't gonna have a problem with the 5w-20 at all if that's what you rather run. __________________ '02 Stang GT Just cause you don't understand what's going on ...don't mean it don't make no sense And just cause you don't like it,...don't mean it aint no good And let me tell you something Before you go taking a walk in my world,...you better take a look at the real world Cause this aint no Mr. Rogers Neighborhood Can you say "feel like shit?"Yea maybe sometimes I do feel like shit I aint happy about it, but I'd rather feel like shit than be full of shit! And if I offended you, Oh I'm sorry, But, maybe you need to be offended But here's my apology and one more thing........Fuck you! Cause you can't bring me down

01-07-2008, 11:32 AM	#11
SCobraVT99 God's gift to Dell Join Date: Mar 2007 Location: Round Rock Posts: 1,202 Trader Rating: (0)	I put Castrol 10W-30

01-12-2008, 05:33 PM	#14
Bigdrumma22 Evil Angel Join Date: Apr 2007 Location: San Antonio, TX Posts: 1,052 Trader Rating: (3)	I use Mobil 1 Full synthetic 5W-30 simply because it's not new anymore and wasn't when I got it. If bearing tolerance has anything to do with it, mine have grown with mileage. I've got a little over 71k, so I don't see an issue with using a little bit thicker oil unless the car is brand new, or you're breaking in the engine. It's not like he's trying to throw straight 40HD in or something. I haven't had any problems and usually get 19-20 mpg. __________________ 2002 Mustang GT, 271hp/306tq on 87 CMR Tune, Roush short throw rally style shifter, King Cobra Clutch, Roush CAI, C&L Plenum, BBK/Roush 75mm T/B, Kooks L/Ts w/catted X, Bassani Cat-back, Eibach Pro-kit Springs, Energy Suspension bushings, KYB AGX's, Hotchkis C/C plates, UPR ProStreet rear control arms, Brembo Drilled/Hawk pads, BFG's, Dual Halo Projector 8k HIDs, Kenwood: KDC-X790, KAC-9102D, KAC-8402; Infinity: 6810CS, 6812CF; Orion: P series subs all powered by Optima My car http://www.cardomain.com/ride/2628572 My truck http://www.cardomain.com/ride/2206751

01-12-2008, 11:25 PM	#15
TonyToughNuts Ya know.....What had happened was....... Join Date: Dec 2007 Location: Ft. Hood Posts: 157 Trader Rating: (0)	holy crap!! 19-20?? see, use 5-20 like it says on yours (and mine) i get 26 if i'm easy and 21 if i'm tearing around. crap. i get 17 doing 135 mph on I-10 between Ft. Hood and Ft. Bliss! and that is stock minus a CAI and a home P&P TB/plenum. __________________ you laugh cause it's funny, i laugh cause it's true

01-13-2008, 09:56 AM	#17
86sleeper Registered User Join Date: Dec 2003 Location: deer park Posts: 2,435 Trader Rating: (0)	i use the non-synthetic 5w30 as that is what my blower likes. __________________ MIKE '86 GT:high 12's Sold '01 GT:low 11's for sale

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