What weight oil do I use - 1998 Lexus ES 300

Use only the oil weight on the oil cap or owners manual if the cap does not list the oil weight. Most older vehicles called for eather 10w30 or 5w30 depending on the ambient temp. In the past 10 or so years, manufacturers updated engines for better fuel efficiency by tightening tolerances in the engines, thereby needing a lighter oil weight to provide sufficient lubrication for the parts So manufacturers started requiring 5w20 oil in their engines. I work as an Auto Care Technician at Walmart, and we will NOT do an oil change for any weight other than the recommended weight by the manufacturer. If it calls for 5w20, we use 5w20, regardless of what the owner wants. This is to avoid any possible engine oil related problems. People will blame someone else if they have a warranty issue the dealer refuses to honor for whatever reason, and it would go back to the last place the vehicle had the oil changed at. So therefore at Walmart, we follow the manufacturers recommended oil weight for all oil changes.

Click on link to view oil guide.http://www.autozone.com/autozone/repairinfo/specifications/specificationsMain.jsp?childCatName=Engine+Oil+Type/Weight/Capacity&childCatId=23200283&categoryNValue=23299999&categoryNameForTitle=Specifications&categoryName=SPECIFICATIONS&childCategoryNameForTitle=Engine+Oil+Type/Weight/Capacity

Only the manufacturer's recommended oil weight should ever be used in your engine.

While using a heavier weight oil might reduce the leakage somewhat, (but not much), the benefit will be more than offset by the internal damage that an UN-recommended oil weight may cause to your engine. The engine was built with certain tolerances between the metal parts, and a higher weight (thicker oil viscosity) may not be able to penetrate the spaces, causing premature wear.

In short, don't do it. Repair the leaky seal, or gasket, and only run what Saturn says you should run.

With any multi viscosity oils the first # represent the viscosity(thickness) at start up temp. The second # represents the viscosity at operating temp. The smaller the # the less the viscosity. So a 10w30 starts at a 10 weight and turns into a 30 weight. The 10w40 starts at a 10 weight and turns into a 40 weight. the w stand for winter. Most people use multi viscosity oils. While some don't likel them they opt to use a SAE30 (straight 30). It is 30 weight all the time. But in most areas in the U.S you should use a multi viscosity oil

Yes. 10-w30 will act like a 10 weight oil when cold and a 30 weight oil when hot. 10-w30 will act like ten weight when cold, but like (thicker) 40 weight oil when hot. Your profile only says Cadillac and doesn't say model or year, but most cars since the early- mid 80's use 5-w30. Always use the oil weight recommended in your owners manual. If you are unsure call the dealer and they will tell you what is right for your car.

HI. The proper weight and type, will be 10W-30.

Drain engine oil and replace oil filter(your local automotive store will have a book telling you what oil filter you need to buy). You've probably been using a multi-grade 10-30 or 10-40 weight oil. Or a straight 30 weight oil. Regardless, replace that oil with one grade heavier, single-weight of oil. During warm months, use 40 weight; in the winter (depending on how far the mercury dips in your part of the country) use 20 or 30 weight. Slightly thicker oil won't hurt that worn engine, and if your battery is good, it'll turn over fast.

The correct oil weight is 5W20, but 5W30 can be used also. Be consistant when using oil, try to use the same brand and always use the same viscosity. This vehicle requires 4.5 liters of engine oil.

O.K. Let's use 20 weight for example. A straight weight oil is just that, a straight 20 weight in viscosity, it doesn't change when it gets hot or is cold, so it won't thin when heated. It will read
sea 20 on the container. A 20/50 has a viscosity that changes when heated. When cold it is a 50 weight, then as it heats up it thins to a 20 weight. A 20/50 might not be too bad to run in this situation, but the viscosity breakdown is quicker with the mixed viscosity oils, so I generally recommend running a straight weight, such as 15 or 20 in the winter, and a 30 or 40 in the summer. Keep in mind that the oil does not thin, so if you have extreme cold in the winter, the car may not start very easy. If it doesn't, then you can go to a thinner oil. In the summer, if you have extreme heat, you can go with a thicker oil if the engine has a little noise, or running hotter than usual. Just remember, the lower the number, the thinner the oil. Running a thicker oil in yours, should cut down on the oil consumption.