TSB 5w30 vs 5w20 on 98 Expedition

[Fitz98]

I was on the Amsoil website looking up a torque spec and they recommended 5w20 for my 98 Expedition.
They said
"Viscosities:
All TEMPS....5W-20 This specification has been updated from 5W-30 to 5W-20 per a Technical Service Bulletin from the manufacturer 5W-20 is the preferred viscosity. "
What would be the reason for a TSB for the lighter weight oil.
In a previous thread about Mobil 1 oil differences, the general concensus was a heavier oil (10w30)

 

[mclasser]

On a 98, I'd just keep running 5w30 and not think twice about it.

 

[Dylan1303]

Fuel economy

 

[burla]

they want you to ruin the truck so you can buy a new one.

 

[JLTD]

I'd be keeping it 30 grade also. What engine - 5.4?

 

[wemay]

20 to 30? It's gotta be a legit engineering issue.
30 to 20? 'Just ignore it'

But in all seriousness, if you've been fine all these years with the 30.... i wouldn't change.

 

[PimTac]

I wonder what date that bulletin was issued?

For a 20 year old vehicle I would stay with what you have been using.

 

[Tdog02]

I'm suspicious of changing anything at this point. Dates would be important on the TSB like PimTac said, but I would keep doing what you are doing.

How long have you had the Expedition and are you having any issues with it??

 

[SwampSurvivor]

I have a 97 F150 engine in my 01 F350. The 97 engine was spec'd for 5w-30 and the 01 engine was spec'd for 5w-20. Apart from the heads being different (mine has the PI heads) , I'm not sure what changed internally.

 

[aquariuscsm]

If it calls for a W30 and you're in Florida? Go with a 10W30.

 

[dave1251]

Originally Posted by PimTac
I wonder what date that bulletin was issued?

For a 20 year old vehicle I would stay with what you have been using.

From what I recall the data was in the early 2000's.

 

[dave1251]

Use what you prefer. The difference between a 20 and 30 grade can be measured comparing human hair.

 

[nascarnation]

Originally Posted by burla
they want you to ruin the truck so you can buy a new one.



Think how many of those 300,000 mile Crown Vic taxi cabs died premature deaths on bulk 5W20.

 

[PimTac]

Originally Posted by nascarnation
Originally Posted by burla
they want you to ruin the truck so you can buy a new one.



Think how many of those 300,000 mile Crown Vic taxi cabs died premature deaths on bulk 5W20.

b is a broken record and then some.

 

[demarpaint]

You're in Florida, and a 30 grade oil got you this far? I'd stick with the 30 grade oil.

 

[ka9mnx]

The change was for CAFE - fuel economy. The bulletin came out in 2002 (TSB 02-1-9).

Correction 2002.

 

[demarpaint]

Originally Posted by ka9mnx
The change was for CAFE - fuel economy. The bulletin came out in 2002 (TSB 02-1-9).

Correction 2002.

Correct. They back spec'd my 93 Aerostar around that time.

 

[ka9mnx]

I believe the first TSB came out in 1999. This revision added many more older engines along with the "exception" vehicles.

FORD:
1992-2002
1993-1994
1993-1997
1993-2002
1995-2000
1998-2002
2000-2002
1993-1996
1993-1997
1993-2002
1995-2002
1997-1999
1997-2001
1997-2002
1999-2002
2000-2002
2001-2002
LINCOLN:
MERCURY:
Article No.
02-1-9
CROWN VICTORIA
TEMPO
THUNDERBIRD
ESCORT, MUSTANG, TAURUS
CONTOUR
ESCORT ZX2
FOCUS
BRONCO
AEROSTAR
E SERIES, F-150, RANGER
WINDSTAR
F-250 LD
EXPLORER
EXPEDITION
SUPER DUTY F SERIES, SUPER DUTY F-53 STRIPPED CHAS.
EXCURSION
ESCAPE
1991-2002
1993-1998
1993-2002
2000-2002
1998-2002
TOWN CAR
MARK VIII
CONTINENTAL
LS
NAVIGATOR
1992-2002
1993-1994
1993-1997
1993-1999
1993-2002
1995-2000
1999-2002
1997-2001
GRAND MARQUIS
TOPAZ
COUGAR
TRACER
SABLE
MYSTIQUE
COUGAR
MOUNTAINEER
This article is being republished in its entirety to
update the vehicle models, engines and years
affected.
NOTE
PLEASE REFER TO THE VEHICLE APPLICATION
LIST LATER IN THIS TSB FOR A COMPLETE
LIST OF VEHICLES AFFECTED BY THIS TSB.
Copyright © 2002 Ford Motor Company
ISSUE
Ford Motor Company now recommends SAE 5W-20
viscosity grade for servicing most gasoline and
flexible fueled vehicles.
ACTION
All 2001 and 2002 vehicles where SAE 5W-20 is
specified should be serviced at the recommended
oil change intervals using SAE 5W-20. This oil is an
improved formulation to improve fuel economy.

 

[ka9mnx]

Ironically, in 1998 Ford issued a TSB (TSB 99-8-16) upping the viscosity from 10w-30 to 5w-30.

PUBLICATION DATE: April 26, 1999
FORD
1989-93 Festiva
1989-94 Tempo
1989-97 Probe, Thunderbird
1989-99 Crown Victoria, Escort, Mustang, Taurus
1994-97 Aspire
1995-99 Contour
LINCOLN-MERCURY
1989-92 Mark VII
1989-94 Topaz
1989-97 Cougar
1989-99 Continental, Grand Marquis, Sable, Town Car, Tracer
1991-94 Capri
1994-98 Mark VIII
1995-99 Mystique
1999 Cougar
LIGHT TRUCK
1989-90 Bronco II
1989-96 Bronco
1989-97 Aerostar, F Super Duty
1989-99 Econoline, F-150, F-250 LD, Ranger
1991-99 Explorer
1993-99 Villager
1995-99 Windstar
1997-99 Expedition, Mountaineer
1998-99 Navigator
1999 Super Duty F Series
ISSUE
ACTION
Ford Motor Company now recommends SAE 5W-30
viscosity grade for servicing any Ford gasoline-
powered vehicle regardless of model year.
When servicing any Ford gasoline-powered vehicle,
use SAE 5W-30 viscosity grade motor oil. Refer to
the following text for further details.
Both SAE 10W-30 and SAE 5W-30 viscosity grade motor oils have been recommended in the past depending
on vehicle model and model year.
Tests have proven SAE 5W-30 viscosity grade motor oil provides the optimum protection and benefits for Ford
gasoline engines. At both high and low ambient temperature conditions, SAE 5W-30 provides the best overall
protection. It allows faster starts under cold ambient temperatures.
SAE 5W-30 also provides approximately 1/2% increase in fuel economy over SAE 10W-30.
SAE 5W-30 viscosity grade motor oils certified for gasoline engines by the American Petroleum Institute (API)
should be used for all service procedures requiring replacement of the motor oil.

 

[Dave9]

Originally Posted by Miller88
I have a 97 F150 engine in my 01 F350. The 97 engine was spec'd for 5w-30 and the 01 engine was spec'd for 5w-20. Apart from the heads being different (mine has the PI heads) , I'm not sure what changed internally.


What changed is they can claim slightly higher fuel economy, have been desperately trying to whittle away at that for decades.