"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.