fan25100

Please, advise on the best practice. In an older Toyota that I used to drive (had almost 150k miles when I first got it), I used oil that's heavier than the specs called for per advise from multiple mechanics. They said, that as the engines wear, the gaps and tolerances increase, and I should switch to the heavier weight oil as the car ages. In the aforementionned Toyota, the specs called for 10w-30. I used 15w-50, with additional mixes. That car is still going strong at almost 300k miles.
Now I have 2004 CRV AWD with 107k miles and the specs call for 5w-20. Please, advise on the best engine oil weight to use at this point in time, and should I switch to heavier weight oil as miles add up, if so, at what intervals, and what weight should I use?

Thank you much!

HondaPartsHero

Use what Honda recommends. I stay away from high mileage oils as well as they tend to only mask other issues. If the car leaks fix it, if it burns you're only prolonging the inevitable. I mean 530 or 10w30 isn't going to kill it but it isn't necessary.

LDForget

the first number in an engine weight is what it is in cold temprate. Most vehicles use to use 10wXX, but have switched to 5wXX or even 0wXX because theyve realised just how slow cold oil gets to the top of our engines. It will also increase starting time. Notice how newer engines start so much quicker? Its not only because of better engine management, but also because of the thinner weight when cold. The second number is how thick the oil is once its reached operating temprature. Honestly, 5w20 is used in 90% of cars now a days, and theres a reason. The oil gallaries in our engines are getting thinner and thinner because were trying to pack more displacement and technology into a physically smaller engine. Dont change it. Infact, using a thicker oil will clog up the oil gallaries in older engines as well, as theres usually deposits in the gallaries partially blocking it in the first place.

exb18c1

Oil companies have increased their reliability over the past few years (via advanced additives,antioxidants etc.)but the main reason to go to thinner oil is to reduce emissions(I guess the DOT forces them to).Anyways stick to the recommended viscosity.

browntown

bobistheoilguy is a good place to research, but as mentioned modern honda engines are built pretty tight, and you shouldn't need to go thicker than spec'd.

My e30 bmw on the other hand, only gets 20w50 because it will leak like a sieve with anything thinner.

steven13

i did not understand your stuff it is not clear to me can i have more information. thanks in advacne.