91 is fine. It's the recommended one. I drive a 430. It's a high compression engine, so you need to use the higher octane. If you use lower, you can feel and smell the difference. And really, I don't think you spend more money, because it goes farther on 91 than it does on 87 in my experience.

For oil, it's very very very debatable about regular vs synthetic, but whatever you use, stick with it from there on out - do NOT switch between regular or synthetic often.

I've stuck to synthetic. I feel that my car runs better on it. Usually mobile one full synthetic, but I'll use Mobile1 extended performance when it's on sale. More important than the brand of oil is the filter. Never use cheap filters. Go with Mobile One, Toyota, or some other ones. Avoid Fram.

 

that is a load of baloney. It used to be the "standard of practice" myth but has since been abandoned by oil makers and consumers. You can switch back and forth between conventional and synthetic as much as you want. Even the oil companies tell you this now on their websites.

steviej

 

I have no idea what the oil makers say/said. I'm going from personal experience. Switching between oils I noticed a big difference. The seals seem to leak if you switch between them often.

 

you guys had me scared so when I stopped by my local Lexus dealing to pick up some filters, the parts guy said he has not heard of any issues with moving from one oil type to another. He said, folks move up to full synthetic after 10-15k miles and some move back, with out much in terms of leaks or issues.

Then my buddy who works for Lexus service (who actually did the oil change for me) told me he's heard that you should stick with one or the other after you switch...so basically, it's probably both! ahahhaaa I know that doens't help, but figure if you start with one, if you can keep it the same, you may want to try to, but if not, switch..just keep an eye out for leaks.

I switched to Mobile 1 (first oil change on my new, used GS 300) and she feels and sounds a little better. I'm also keeping an eye out for leaks or drips of any kind, since the other posts here freaked me out

 

I switched back and forth ***** nilly depending on my mood on an old taurus and it never had any leaks or burned any oil (not to make it sound like it was reliable, it had tons of issues but nothing engine related before I got rid of it!).

I really don't think there is much of any noticeable change in how an engine actually performs between fresh synthetic and french dino oil... it all boils down to placebo affect. I'll probably just continue changing my oil with whatever Toyota puts into the engine by default when I have the oil changed as since I moved into a condo it's way too inconvenient to change it myself (and against the condo rules...). I do change my oil a bit ahead of the standard service schedule anyway.

 

I think popular wisdom is switch back and forth if you have always done so and you have a younger mileage engine. If you have never used synthetics and you have high miles, stick to conventional.


I have no issues switching or using blend. For my older GS I use conventional and the newer one I use synthetic.

 

it looks like costco is having a sale on mobil 1 oil. $9 off a case of 6 quarts or something like that. my questions for yous is: how long can i store engine oil in my garage? of course i won't open it any of it and it will be in a cool, dry place.

does oil ever go "bad"?

 

Not really as long as the seal isn't broken, if it's been opened, then it can go "bad" for the same reason it goes bad in the engine, it absorbs moisture from the air.

Think about it, that oil (dino) has been sitting in the ground since, well, the dinosaur age or earlier... and is in fact, made out of dinosaurs, dinosaur poop, early man, early man poop, trilobites, stonehenge alien poop, and william wallace.

 

^^ Rofl!

Anyways, I was wondering if I should switch to an oil of different weight like Mike said for better performance since I push my car fairly often. I often hear the oil pump on first start ups and every now and then while I drive. I also live in SoCal where the max temperature the car is exposed to 50-100. I'm not exactly sure what the numbers mean either XW-XX if anyone could briefly tell me. Haha thanks!

 

http://lmgtfy.com/?q=what+do+motor+o...rades+mean&l=1