Engine Oil Change Interval for a car that is not used much ?

white91

Member
Mar 1, 2004
14
2
13
Hello, I have a 1991 GT, that I have had since new.

It currently has 39000km (24500mi) on it.

I have always changed the oil every 5000km, or every year, which ever occurs first.

I have now also added a 2008 GT convertible to my collection.

Both cars will get driven during the summer, on weekends, when it is sunny.

My 91 GT is lucky to go through 3 tanks of gas a year, and I would expect the 2008 GT to be used about the same.

Both cars would get less than 20 hours of use per year.

My question concerns how often the oil needs to be changed? Does the filter need to be changed too?

Most manufacturers seem to time the oil changes after about 100 hours of usage.

It just seems that it is wasteful to change the oil with so few hours of usage.

Has anyone who uses their cars as much as I do, ever had the oil analyzed to see if it actually needs to be replaced?

Also, I have heard the old adage that says "oil is cheap, motor repairs are expensive", but I am looking for a scientifically based opinion.

As an example, my 2016 John Deere tractor has oil change intervals based strictly on hours of operation, there is no seasonal requirement to change the oil according to the dealer.

I would imagine that someone who has multiple vehicles in their collection, that see limited usage, would be able to provide their thoughts on this.

Thanks for your input,
Matt.
 
  • Sponsors(?)


Potomus Pete

Is there a trick , or does my wife just hold it
Mar 7, 2019
1,076
356
93
56
Sarasota Florida
Bump.......Me too is it bad to over do oil changes. I change mine every six months even if it has two hundred miles a year. I use Motorcraft from Walmart. Thirty bucks for everything
 

stormsedge

Active Member
Jun 17, 2018
304
89
38
Here
This is what I do (hence, my opinion)...I changed my Mustang GT (2000 with 92k miles) a couple of weeks ago at just over the 14 month mark and less than 3500 miles. One year or 5000 miles is my target. I use Mobil 1 Extended Performance High Mileage Formula (15k miles). If I were racing it, I'd change it much more frequently to keep an eye out for metal in the oil.

I change my F250 6.0 Powerstroke at every 5000 miles (target), but it is often less than 5k because the diesel collects soot in the oil (worse with in town driving) and it causes the engine to run idle rough and act up when the soot clogs the injector oil passages.

I change Mrs' car every 5000 miles without regard to a timeline...and she usually drives between 12-15k a year.

Always change the filters...note--some industrial/marine applications change filters on a regular schedule while only changing oil when it fails testing.

Hope this helps.
 
Last edited:

redNfast

Active Member
Apr 5, 2020
68
33
28
74
Woodstock, GA
If in doubt, why not use the oil monitor ? First hit (change oil) change the oil . One can notice the frequency or miles driven will change with how the car is driven.

City, highway or track for instance.
 
  • Haha
Reactions: Monkeybutt2000

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
33,310
9,610
224
Massachusetts
Long story short, old oil tends to contain byproducts if conbustion, fuel, moisture and other residues that can form an acid and attack parts of your motor.

I recommend an oil change at least yearly before storage if the car. For instance, if you are parking the car in Oct until April, I would take it out for your last cruise, change the oil, then let it sit with fresh clean oil over the winter.


I drive my car 200 miles a year, I change the oil before storage.
 
Last edited:
  • Like
Reactions: Gs87GT

Steel1

Mustang Master
Aug 18, 2017
1,103
495
113
51
Connecticut
My 93GT sees a few hundred miles a year, my routine is to change oil and filter at the end of the season before storage
and again in the spring.
Probably overkill but something about the oil sitting in the pan over the winter in my garage which can get pretty cold makes
me think I should dump it in the spring.
15w50 Mobil 1.
 

foxbodybill89

Member
Jan 19, 2020
21
3
13
31
Sioux Falls, SD
I've done something similar, change the oil before winter storage with some cheap generic oil, run it just long enough to circulate the new oil and get the residual old oil into the pan, then change it again in the spring with the good oil. The cheap oil over the winter basically just preserves the engine, you're not driving on it. Don't do this anymore since car has 95000 on it, but I would do this for a new or rebuilt engine.
 

7991LXnSHO

Now I want a 10 year badge
10 Year Member
Sep 1, 2010
2,993
543
154
Kearney, NE
Changing oil that has not been run enough to get blow by in it is really not necessary.
The oil was in the ground for a long time. In it’s refined state, the oil will not deteriorate in that amount of time. The additives will not have a chance to be used up in a cold, parked motor either.
The idea of reusing an oil filter is FAR more concerning to me. The filter media, cardboard and adhesives in low end filters is much more likely to break down over time than slightly used oil is. After the recent wave of You Tube filter comparisons, I saw some brands have changed since I last worked a parts counter where we set up displays with opened filters. Wix/Napa Gold is now the only brand I trust on an engine for more than a year. My back stock of orange ones were rusting inside and went to the landfill unused.

My 93GT sees a few hundred miles a year, my routine is to change oil and filter at the end of the season before storage
and again in the spring.
Probably overkill but something about the oil sitting in the pan over the winter in my garage which can get pretty cold makes
me think I should dump it in the spring.
15w50 Mobil 1.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
17,184
5,494
193
polk county florida
Changing oil that has not been run enough to get blow by in it is really not necessary.
The oil was in the ground for a long time. In it’s refined state, the oil will not deteriorate in that amount of time. The additives will not have a chance to be used up in a cold, parked motor either.
The idea of reusing an oil filter is FAR more concerning to me. The filter media, cardboard and adhesives in low end filters is much more likely to break down over time than slightly used oil is. After the recent wave of You Tube filter comparisons, I saw some brands have changed since I last worked a parts counter where we set up displays with opened filters. Wix/Napa Gold is now the only brand I trust on an engine for more than a year. My back stock of orange ones were rusting inside and went to the landfill unused.
An old mechanic friend laughs at me because I use wix filters, they started out as an industrial filter manufacturer, been around a long time.
 

Gs87GT

Active Member
Sep 25, 2019
238
77
38
Penn's Woods
Every 5k miles or one year for me, for reasons stated by mustang 5l5. 7991lx is also correct. Oil and filter both regardless.

To me, changing in the fall and then in the spring seems like a big waste. I hope you capture that virtually unused oil and use it for chain saw bar/chain lube or something. Wix filters are good. I use fram ultra which it's an excellant filter and so are royal purple filters.
 
Thread starter Similar threads Forum Replies Date
S Oil change time interval? SN95 4.6L Mustang Tech 12
2000fordstanggt Royal Purple oil change intervals (time) SN95 4.6L Mustang Tech 16
scarpi Oil change interval 2005 - 2009 Specific Tech 8
JBushman73 Intervals between oil changes? Synthetic SN95 4.6L Mustang Tech 24
C Oil Change Interval Question??? SN95 4.6L Mustang Tech 4
mattkimsey Amsoil oil change intervals? Fox 5.0 Mustang Tech 8
LILCBRA Oil pan gasket change OR starter replacement in a 302 II 1974 - 1978 Mustang II Talk & Tech 11
92j3ieje8 How many miles is an oil change needed for a v6 o4 mustang? 1996 - 2004 SN95 Mustang -General/Talk- 0
1 Oil change question 1965 - 1973 Classic Mustangs -General/Talk- 4
A Auto Transmission oil change. 2015+ (S550) Mustang -General/Talk 3
R Fox oil change 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 23
C 98 GT - Don't see oil level on the dipstick after an oil change SN95 4.6L Mustang Tech 2
E Oil change for modify GT SN95 4.6L Mustang Tech 2
M Please Help and Advice The Welcome Wagon 4
0 03 Mustang v6 .....Rpm dropping/ New oil Change SN95 V6 Mustang Tech 0
1 Engine 1995 Mustang GT 1994 - 1995 Specific Tech 0
Blucifer99 Engine 1992 mustang oil pan capacity with and without filter change Fox 5.0 Mustang Tech 22
D First oil change? 2015+ (S550) Mustang -General/Talk 10
GrandmasterK Check Oil Light After Oil Change Fox 5.0 Mustang Tech 5
EXTRPR50 Oil Change Mess! Wth?? 2005 - 2009 Specific Tech 7
Sketchy_GT Oil/oil Change Fox 5.0 Mustang Tech 24
Debrajean70 Check Engine Light On 2004 Stang Gt With Low Milage!! The Welcome Wagon 5
D Installing Mgw Shifter And Changing Trans Oil. Can I Do It In My Garage? 2010 - 2014 Specific Tech 6
NJBob Oil Change Indicator 2015+ (S550) Mustang -General/Talk 8
KENS89LX Changing Oil Cooler Adapter Gasket SN95 4.6L Mustang Tech 6
NJBob Oil Change - Does Ford Plug In 2015+ (S550) Mustang -General/Talk 3
O Change Out Distributor Now The Oil Pump Not Working 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 7
Still Bill First Oil Change 2015+ (S550) Mustang -General/Talk 7
M Engine No Oil Pressure 5 Min After Oil Change SN95 4.6L Mustang Tech 5
newedgejay Oil Change. SN95 4.6L Mustang Tech 7
8 Water In Oil After Intake Manifold Gasket Change Fox 5.0 Mustang Tech 4
from6to8 Want To Change Out The Oil Tube..............few Questions 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 0
B 95 3.8l Noise After Oil Change 1994 - 1995 Specific Tech 1
oneslowgt Another Oil Change Question Xd 1994 - 1995 Specific Tech 5
D Heavy Vibration @ 3-3500 After Changing Oil Pump Fox 5.0 Mustang Tech 7
Slo5Oh89 Oil Pan Change. 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 16
T Has Anyone Changed The Oil Pan Gasket With Motor Still In The Car? 1994 - 1995 Specific Tech 13
The_Grayt_1 Oil change time for my new 02 GT, time vs mileage on oil changes? SN95 4.6L Mustang Tech 14
D Oil Change 2010 - 2014 Specific Tech 2
Tron84 First Oil Change Filter Dissection Pics 2010 - 2014 Specific Tech 4
D 5.9 Oil Change 2010 - 2014 Specific Tech 7
Tim65GT Changing Oil Pan - Gasket is a PITA Classic Mustang Specific Tech 8
BlackBuggy 5.0 Coyote Oil Change 2010 - 2014 Specific Tech 3
BlackBuggy Coyote 5.0 Oil Change 2005 - 2014 S-197 Mustang -General/Talk- 2
brakeswhatbrake 79 5.0 LX automatic wont start after changing oil pump Fox 5.0 Mustang Tech 3
C Changed my oil today... 1996 - 2004 SN95 Mustang -General/Talk- 4
B How to change your oil with Full Synthetic Oil Classic Mustang Specific Tech 0
B How To Change Your Oil with Full Synthetic Oil SN95 4.6L Mustang Tech 1
Sonic04GT First oil change! What type? 1996 - 2004 SN95 Mustang -General/Talk- 42
B engine knock after oil change Classic Mustang Specific Tech 5
Similar threads