Date: Sat, 10 Mar 2007 09:25:22 GMT From: johannes <johsnospamfinospamtter.com> Subject: Re: SAAB 9-5 fluid changes
- Bob - wrote: > > On Fri, 9 Mar 2007 16:05:16 -0800, "Richard Sauer" > <chongkilnospamast.net> wrote: > > >> forever, > >> it only needs topping up. > > > >Thanks. To give an example of how contentious the question of frequency of > >oil change is ..here is what Deanna Sclar has to say in Auto Repair for > >Dummies (Please no jokes)..."If you do a lot of stop-and-go driving in city > >or rush-hour traffic, change your oil as often as every 1000 miles. Your > >engine rarely gets hot enough to evaporate the water that forms in the > >crankcase and builds up sludge in the engine. Some auto repair experts > >believe that it's more accurate to determine how often you should change > >your oil by the number of cold starts your engine experiences than by the > >number of miles it's driven." If she is right, and I have no idea if she > >is, that adds up to a lot oil. > > Nonsense. While short trips to require more frequent change intervals, > no one with a clue suggests 1K changes. If you want some scientific > facts, go out to bobistheoilguy.com and look into the guys actually > testing their oil in labs. > > There are Saab engines running over 300K miles without major rebuilds > on 3K dino and 5K synthetic changes. There's plenty of evidence to > suggest that even that is more frequent than needed - see the guys > testing oil (above). Yes, 1000 miles interval is definitely too short. I change at around 4000 miles with a lot of motorway driving. It feels like the engine sounds better after a change. > >On Coolant she says " You should definitely > >change your coolant in two situations. The first is if you haven't changed > >it a year or in the past 20,000 miles." > > A little shy, but not as bad as her oil claim. 2 years or 24K miles. > The reason is that the anti-corrosive compounds can break down. Use > Saab coolant. Depends on what it says on the tin. You can now get 3 or 5 years lifetime for coolant products. Naturally, it needs topping up if the level goes down. > >Additionally she seems to be > >suspicious of the manufacturer's recommended intervals for oil changes for > >the simple reason that the manufacturer wants you to buy another car, and > >steps to lengthen the life of your present car are not in the manufacturer's > >interest. > > Total BS. Warranties are 100K on a lot of motors these days. They want > them to last. Plus, if she was right, why don't the oil companies > promote shorter change intervals ? Why don't auto mechanics working on > their own cars go with shorter intervals ? However, I still think manufacturers are short sighted. Companies often replace their cars after 3 years (uk) because they expect everything to be totally reliable during that period. An older car is seen as a hazard as it could break down on the way to an important meeting or function. A three year old car has depreciated to about ~40% , but this gives us a nice supply of excellent secondhand cars. But around that time the car gets a kind of mid-life crisis; clutch, brakes, timing belts, drive belts, bulbs and other niggles, it's almost as if this was designed that way.