is 5000 miles too long to wait for an oil change?

[bronsin]

I think the oil change intervals are longer because of FI. WHen engines had carbs you were warned not to idle the engine. I think thats because the mixture in a carbed engine at idle is too rich. And imprecise at all speeds in general. I know changing the oil in my 74 VW Beetle every 2k miles the oil smelled of gasoline.

With FI the mixture is very nearly correct for all rpms. When I change the oil in my FI cars at 6k miles the oil smells like it did coming out of the bottle.

Also in general an engine that is driven longer distances between startup and shutdown is less hard on its oil than one that is driven short distances. The longer your drive interval the longer you can go between changes. Short distance driven vehicles, like my Yaris, need more frequent changes.

[nookandcrannycar]

Originally Posted by bronsin

I think the oil change intervals are longer because of FI. WHen engines had carbs you were warned not to idle the engine. I think thats because the mixture in a carbed engine at idle is too rich. And imprecise at all speeds in general. I know changing the oil in my 74 VW Beetle every 2k miles the oil smelled of gasoline.

With FI the mixture is very nearly correct for all rpms. When I change the oil in my FI cars at 6k miles the oil smells like it did coming out of the bottle.

Also in general an engine that is driven longer distances between startup and shutdown is less hard on its oil than one that is driven short distances. The longer your drive interval the longer you can go between changes. Short distance driven vehicles, like my Yaris, need more frequent changes.

^^^^^ The shortest interval for me has been 3k and the longest about 17k. When I first changed my spark plugs at about 208,000 I'd had the oil changed about 17-19 times before that (I don't have my log book handy) and the Toyota dealer said my engine was in great shape, and not burning any oil at all.

[Absolutely Red 12]

Originally Posted by bronsin

I think the oil change intervals are longer because of FI. WHen engines had carbs you were warned not to idle the engine. I think thats because the mixture in a carbed engine at idle is too rich. And imprecise at all speeds in general. I know changing the oil in my 74 VW Beetle every 2k miles the oil smelled of gasoline.

With FI the mixture is very nearly correct for all rpms. When I change the oil in my FI cars at 6k miles the oil smells like it did coming out of the bottle.

Also in general an engine that is driven longer distances between startup and shutdown is less hard on its oil than one that is driven short distances. The longer your drive interval the longer you can go between changes. Short distance driven vehicles, like my Yaris, need more frequent changes.

Absolutely correct!!