• Mustang Forums
  • 2005 - 2014 S-197 Mustang -General/Talk-
  • 2005 - 2009 Specific Tech

5w-20 Ford and CAFE

  • Thread starter Thread starter JTGrant
  • Start date Start date Jan 2, 2006

JTGrant

New Member
Aug 2, 2005
775
0
0
GA
Jan 2, 2006
#1
  • Jan 2, 2006
  • #1
I contacted a rep. from Ford about a month ago. My question was if I drive the car in hot temps all the time could I run a 5w-30? They responded with "Contact your local dealership and talk with them about your oil question." So I emailed them back and said well I thought Ford would void warranties if they found out that you were running anything but 5w-20. Again they responded with the same statement. I also told them that I could care less and fuel economy and that I would rather have more protection. They would never give a straight answer, nor did they claim to void my warranty. Just Ford for thought!
Also post what oil you are running.
 

91mini

Member
Dec 6, 2004
115
0
16
Jan 2, 2006
#2
  • Jan 2, 2006
  • #2
I run 5w-30 in my stang. It's easier to find than the 5w-20 in Mobil one oils around here. I don't see why that would void your warranty though.
 
T

trey929rr

New Member
Dec 5, 2005
13
0
0
Jan 2, 2006
#3
  • Jan 2, 2006
  • #3
I Heard even though the 5w-20 is thinner, it protects very well so i'll prolly go with that. I don't care about mpg either so if 5w-30 protects better then i would rather use that.
 

351CJ

New Member
Dec 11, 2002
1,732
1
0
Jan 2, 2006
#4
  • Jan 2, 2006
  • #4
A heavier weight oil does not always give your engine "more" protection.

A 5w30 oil can be inferior to a 5w20 because to get the greater viscosity range the oil must have more viscosity enhancers in it.

VEs lower the "protection" because there are less lubricating molecules in the oil (putting in more VEs in means something else has to come out of the oil).

More VEs also reduce the oil's ability to suspend contamanents (again less lubricating molecules in each quart of oil). When an oil no longer can hold contamenents in suspension, the oil's useful life has ended and sludge starts being deposited in the engine.

A synthentic oil or synthetic blend is also much better than a conventional oil because synthetics require less VEs to be added to optain the desired viscocity range, which once again means that in each quart of syn or syn blend oil there are more lubricating molecules because fewer additives are needed.
 

Edbert

Founding Member
Jul 13, 2002
3,548
32
109
Austin TX
Jan 2, 2006
#5
  • Jan 2, 2006
  • #5
The proper viscosity to use also has a lot to do with the tolerances used when the engine was constructed.

I have a hard time recommending anything other than what those standing behind the warranty say to use. On the other hand 20 versus 30 is a minor jump.
 
T

trey929rr

New Member
Dec 5, 2005
13
0
0
Jan 2, 2006
#6
  • Jan 2, 2006
  • #6
Edbert said:
The proper viscosity to use also has a lot to do with the tolerances used when the engine was constructed.

I have a hard time recommending anything other than what those standing behind the warranty say to use. On the other hand 20 versus 30 is a minor jump.
Click to expand...
yeah especially since mobil 1 5w-30 is on the thin side of the 30 weight.
 
S

shooterm1

New Member
Jul 18, 2005
540
1
0
Milford, Pennsylvania USA
Jan 2, 2006
#7
  • Jan 2, 2006
  • #7
JTGrant said:
I contacted a rep. from Ford about a month ago. My question was if I drive the car in hot temps all the time could I run a 5w-30?
Click to expand...


That's a great question and very I'm disappointed that Ford flaked out on giving you a straight answer.

For those of us who drive in the Desert Southwest where mid-day temps frequently exceed 110F, this is no small matter of idle curiosity but a serious engineering dilemma.
 

JTGrant

New Member
Aug 2, 2005
775
0
0
GA
Jan 4, 2006
#8
  • Jan 4, 2006
  • #8
Mobil 1 5w20 or Mobil 1 5w30 extended performance? I have looked at the number and 5w30 ext. performacne is almost the same weight. But with better anit-wear additives. 5w20 just makes me nervous. I guess times are changing hell I remember when everyone thought 5w30 was too thin.
 
M

Madhouse

New Member
Dec 10, 2002
201
0
0
Houston, TX
Jan 4, 2006
#9
  • Jan 4, 2006
  • #9
I run Mobil-1 10W-30 in both my Mustang and my Lightning.
 
A

Alec

New Member
Jul 15, 2004
63
0
0
Jan 4, 2006
#10
  • Jan 4, 2006
  • #10
Use Motorcraft semi-synthetic 5w-20 and drive that baby It's cheap, you can get it at Wal-Mart, Autozone etc..

edit..Read this page and the index.
Oil info overload

http://63.240.161.99/motoroil/108.html
 

JTGrant

New Member
Aug 2, 2005
775
0
0
GA
Jan 4, 2006
#11
  • Jan 4, 2006
  • #11
5w-30 extended performance it is
 

GOLDENPONY

Founding Member
Jan 23, 2002
1,503
0
36
LOVELAND, OHIO
Jan 5, 2006
#12
  • Jan 5, 2006
  • #12
Oil

I use Mobil 1 5W20
 
T

T4B

New Member
Sep 17, 2005
21
0
0
VA
Jan 7, 2006
#13
  • Jan 7, 2006
  • #13
Mobil 1 5w30 here. Used on my '66 and '03 GT (when I had it) too.
 
You must log in or register to reply here.

Similar threads

B
2001 roush stage 3 - sat for 5 years
  • Brando_05
  • Aug 26, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
249
1996 - 2004 SN95 Mustang -General/Talk- Aug 26, 2025
Brando_05
B
6
Hey all,I’m putting together a 302 for my 1968 Mustang and wanted to post the combo + some questions to make sure I’m not missing crucial
  • 68_Disgustang
  • Feb 22, 2026
  • 1965 - 1973 Classic Mustangs -General/Talk-
Replies
4
Views
813
1965 - 1973 Classic Mustangs -General/Talk- Jun 20, 2026
gray owl
G
S
Drivetrain 8.8 Pinion and 302 rear main seal leaks after replacing. 93 5.0 with t-5
  • Steigy4827
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
10
Views
645
Fox 5.0 Mustang Tech Apr 1, 2026
Steigy4827
S
P
High idle issue and leaking after running.
  • PHoffman
  • Dec 24, 2024
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
1
Views
460
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Dec 24, 2024
General karthief
Might have to get a Dart block but don't want to and if I do, then 363 instead of 331. Thoughts on what I've already bought so far.......
  • from6to8
  • Jul 8, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2 3
Replies
52
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jul 9, 2025
from6to8
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 2005 - 2014 S-197 Mustang -General/Talk-
  • 2005 - 2009 Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?