car engine oil extended change
 

Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say
around 5000 miles, mainly
on fairly short distances around town. what would be the 'time' limit to
reasonably extend oil changes for economy reasons using a semi synthetic oil
?

I suspect a lot of people will immediately say don't economize in this way.
However some forty years ago I had a conversation with a professor of an
engineering college and he said engine oil does not degrade 'time wise' as
fast as most people think ( and importantly as the oil companies would wish
us to
believe). So by how much time could one reasonably delay an oil change with
modern oils?

car engine oil extended change
 

jw 1111 wrote:

> Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say
> around 5000 miles, mainly
> on fairly short distances around town. what would be the 'time' limit to
> reasonably extend oil changes for economy reasons using a semi synthetic
> oil ?
>
> I suspect a lot of people will immediately say don't economize in this
> way. However some forty years ago I had a conversation with a professor of
> an engineering college and he said engine oil does not degrade 'time wise'
> as fast as most people think ( and importantly as the oil companies would
> wish us to
> believe). So by how much time could one reasonably delay an oil change
> with modern oils?

I think oil and engine technology has changed somewhat over the past 40
years, so your conversation may not have much relevance :-)

I don't think the issue is one of time related degradation, more the
assumption that a car that does a low annual milage will mainly be doing a
lot of short trips. The problem then is that the oil is never sustained at
an elevated temperature, so contaminants remain in the oil. Of course, if
your low annual milage is done by virtue of only a few long trips it may
not be such a problem.

I have seen this, where a car doing a lot of short trips goes on a longer
journey. The oil level will be OK before leaving, but may drop below the
minimum during the trip as the the condensation boils off.

The rule of thumb for a car doing low annual milages is to halve the service
interval. In your case, I would at the very least do an oil and filter
change once a year. The cost of this when viewed against the total cost of
ownership is very small, especially if you are able to DIY it.

HTH

Chris

--
Remove prejudice to reply.

car engine oil extended change
 

"jw 1111" > wrote in message
...
> Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say
> around 5000 miles, mainly
> on fairly short distances around town. what would be the 'time' limit to
> reasonably extend oil changes for economy reasons using a semi synthetic
oil
> ?

with this kind of small mileage you should at least do a 12month oil change,
if not 6 monthly; if you intend to keep the car for a fair time.

Tim..

car engine oil extended change
 

jw 1111 > wrote

> My car (toyota petrol 1.3) does a smallish mileage in a year say around
> 5000 miles, mainly on fairly short distances around town. what would be
> the 'time' limit
> to reasonably extend oil changes for economy reasons using a semi
> synthetic oil ?

Dont bother changing it.

> I suspect a lot of people will immediately say don't economize in this
> way.

Yep, plenty dont have a clue about the basics.

> However some forty years ago I had a conversation with a professor of an
> engineering college and he said engine oil does not degrade 'time wise'
> as fast as most people think ( and importantly as the oil companies would
> wish us to believe).

He's right.

> So by how much time could one reasonably delay an oil change with modern
> oils?

Once every decade is more than you need.

car engine oil extended change
 

On Sat, 04 Mar 2006 08:56:01 GMT, "jw 1111"
> wrote:

>Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say
>around 5000 miles, mainly
>on fairly short distances around town. what would be the 'time' limit to
>reasonably extend oil changes for economy reasons using a semi synthetic oil
>?
>
>I suspect a lot of people will immediately say don't economize in this way.
>However some forty years ago I had a conversation with a professor of an
>engineering college and he said engine oil does not degrade 'time wise' as
>fast as most people think ( and importantly as the oil companies would wish
>us to
>believe). So by how much time could one reasonably delay an oil change with
>modern oils?

Your problem has to do with oil contamination not mileage or
oxidation. If you don't get the oil up to engine temp ( somewhat over
the boiling point of water for the oil, but I've never measured it ),
condensates will accumulate in the oil. Gasoline, water vapor, who
knows what from crankcase fumes. Pretty soon, if you never let your
engine run long enough to boil off these volatile condensates, you've
got acidic crap pumping through your engine that is going to dilute
the lubricity and other wear-resistant characteristics of the oil,
which will lead to early engine death.

So you have to change your oil just as often as anyone else, but for
the contamination reason. You'll have pea soup in the oil sump
eventually, or worse, gunk that will clog the minute oil galleries
that lube the piston bearings and piston pin ( I call it the pin...the
rod that the head pivots on ).

Say at least every 6 months, every 4 months would be better.

Otoh, I'm using full synthetic, and am going by miles not time...5,000
miles change filter and add oil to bring up to full mark on oil stick
( say just less than a full quart for the filter ). And at 10K miles
a complete oil and filter swap.

For me, that means a new filter and somewhat less than a full quart at
25,250 miles, regardless of how long it takes me to get to that
mileage. Then at 30,250, I change ALL the oil and put on a new filter
again.

YMMV
HTH

Lg

car engine oil extended change
 

"jw 1111" > wrote in message
...
> Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say
> around 5000 miles, mainly
> on fairly short distances around town. what would be the 'time' limit to
> reasonably extend oil changes for economy reasons using a semi synthetic
> oil ?
>
> I suspect a lot of people will immediately say don't economize in this
> way.
> However some forty years ago I had a conversation with a professor of an
> engineering college and he said engine oil does not degrade 'time wise' as
> fast as most people think ( and importantly as the oil companies would
> wish us to
> believe). So by how much time could one reasonably delay an oil change
> with
> modern oils?
>

Well I always buy a car from new, and keep it 7 or 8 years, typically doing
100 - 130k miles over that time.
Never have them serviced, and just keep the fluids topped up.
Haven't 'lost' an engine yet. How many car breakdowns do you see by the side
of the road due to 'inadequate oil changes"?
Yea you might get a bit of extra wear, but hey, an engine will be scrapped
typically before its 150k mile birthday, well before its expiry date.

This is all myth and magic to get punters to shell out on expensive oil and
spares.

As long as you keep all your fluids topped up it'll be fine IMHO

Kev

car engine oil extended change
 

"jw 1111" > wrote in message
...
> Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say
> around 5000 miles, mainly
> on fairly short distances around town. what would be the 'time' limit to
> reasonably extend oil changes for economy reasons using a semi synthetic
> oil ?
>
> I suspect a lot of people will immediately say don't economize in this
> way.
> However some forty years ago I had a conversation with a professor of an
> engineering college and he said engine oil does not degrade 'time wise' as
> fast as most people think ( and importantly as the oil companies would
> wish us to
> believe). So by how much time could one reasonably delay an oil change
> with
> modern oils?
>

I revcently had this argument with a Mercedes main dealer.
I have one car that does very little mileage.
Thier position is that its not "10,000 miles or one year whichever comes
first",
its every 10,000 miles.
So the car should not be serviced until the indicator on the dashboard says
so.
They say its because of the more modern engine oils.
Personally I would rather pay for an oil change every year regardeless of
anything else that needed done.

car engine oil extended change
 

In article >, jw 1111
says...
> Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say
> around 5000 miles, mainly
> on fairly short distances around town. what would be the 'time' limit to
> reasonably extend oil changes for economy reasons using a semi synthetic oil
> ?
>
EXTEND? You must be kidding. You surely mean REDUCE?

> I suspect a lot of people will immediately say don't economize in this way.
> However some forty years ago I had a conversation with a professor of an
> engineering college and he said engine oil does not degrade 'time wise' as
> fast as most people think ( and importantly as the oil companies would wish
> us to
> believe). So by how much time could one reasonably delay an oil change with
> modern oils?
>
On a low mileage car used on short journeys you need to be changing the
oil MORE OFTEN, not less. If you are doing 5000 miles a year then once
a year is about right.


--
Conor,

Same ****, different day.

car engine oil extended change
 

"Kev Dyson" > wrote in message
...
>
> "jw 1111" > wrote in message
> ...
>> Hi, My car (toyota petrol 1.3) does a smallish mileage in a year say around
>> 5000 miles, mainly
>> on fairly short distances around town. what would be the 'time' limit to
>> reasonably extend oil changes for economy reasons using a semi synthetic oil
>> ?
>>
>> I suspect a lot of people will immediately say don't economize in this way.
>> However some forty years ago I had a conversation with a professor of an
>> engineering college and he said engine oil does not degrade 'time wise' as
>> fast as most people think ( and importantly as the oil companies would wish
>> us to
>> believe). So by how much time could one reasonably delay an oil change with
>> modern oils?
>>
>
> Well I always buy a car from new, and keep it 7 or 8 years, typically doing
> 100 - 130k miles over that time.
> Never have them serviced, and just keep the fluids topped up.

You sound like you are probably doing lots of miles at a time that's much better
for the engine than doing fewer.

car engine oil extended change
 

In article >, Kev
Dyson says...

> Yea you might get a bit of extra wear, but hey, an engine will be scrapped
> typically before its 150k mile birthday, well before its expiry date.
>
My mates Vectra is currently on 239,000 on its original engine and
turbo.


--
Conor,

Same ****, different day.