Oil grade data.

[SentraSE-R]

Originally Posted by olds455

Don't be discouraged by the worries of the thinner oils. Your car will have been replaced before that difference (if any) would show itself. My '95 Chevy 5.7 has 210,000 miles on it with 0w-20 iused in it since around 20k miles. My change intervals are 10k for a filter and 30k for everything. The truck doesn't use any oil between filter changes and has the probably never been driven without seeing full throttle. The truck will likely rust away before the engine dies....

Those import engines have to work a lot harder than your truck engine, so your comparison isn't transferable to them. The Yaris and Corolla engines make ~70 bhp/liter (106 hp/1.5 liter from the Yaris, and 125 hp/1.8 liter from the Corolla). Your truck only produces ~36 hp/liter (210 hp/5.7 liters).

[Sean.Heihn]

Sentra, sorry to throw a monkey wrench in to your argument, but look at http://priuschat.com/attachments/toy...ons-pdf.49252/. That's a Toyota oil application chart for Canada, same cars and same engines as the US, yet Toyota has okayed use of 20 weight oils there for years. 1998 is the year the N. American Corolla began production at NUMMI using the US produced 1ZZ-FE engine, that engine was designed and tested to use either a 20wt or 30wt. Also, the 1NZ-FE engine used in the Echo and Yaris was adapted from the 1NZ-FXE that was designed for the original Prius and has always used 20wt (1NZ-FXE). The only difference between the 1NZ-FE and FXE is cams and pistons, all other parts are identical, as verified by part #s, including all bearings. In Canada and other countries, the Echo/Yaris has always been able to use 20wt. It's Toyota US that has disallowed the use of lighter oils for warranty purposes, unless they say so. If my car wasn't still under the powertrain warranty, I would be using 0w or 5w20. Thick oils don't necessarily protect better than thin oils, the important criteria is film strength, which is independent of viscosity.

[SentraSE-R]

I'm happy to admit that your facts are irrefutable, and I stand corrected.