shipo

@NDNV Don't confuse them with the facts.

MQAcuraEL

Look guys no need to get into insults. I am fully aware of what it says in the manual. However, you are making no distinction between a brand new engine under warranty and a fifteen-year-old engine that I assume has exhibited wear. You both think that you know far more than the mechanic who services the vehicle. I would just suggest the original poster take ''forum experts''
with a grain of salt

Roadster33

LOL... I dont doubt what YOUR owners guide says or if 5W20 isant the recommended oil. Read my post again, anyways ill get my owners guide reference for you, might take time ive no idea where it is!

Dont be blinded by your own facts, other peoples facts can be equally blinding.

Absolutely agree here. This topic and question has been flogged to death. TS should just do a google search. Ive owned many cars, if its more than 10 years old and has high mileage id move them up the weight. Ive never had any issues with my engines, none of them had starting issues, seized, sludged or had crap in them moving up the weight. The only thing i do without fail is follow the service intervals & use good filters.

Heres a link i found on Mobil - https://mobiloil.com/en/faq/ask-our-...as-engines-age &

Look at the oil viscosity guide from Liqui Moly for an EU 1.7 ES civic -
https://www.liqui-moly.com/en/service/oilguide.html#oww:/api/v1/oww/101/MYS/ENG/1/a937d21e0320b357/faf3958fbe34554f/7c8d26b1b6750c94d86d7a024b0c7b3a/ its either x30 or x40. Obviously your location matters. My point is this engine works fine with heavier oils and it wont shoot up to space and disappear if you use something heavier than recommended for an aged/high mileage motor.

Cheers
R

If the mech youre going to is a decent bloke, then ask him maybe he's seen some symptoms.

shipo

Being a mechanic does not imbue someone with knowledge greater than the engineers who designed the car. Some of the very worst automotive advice I've ever heard spoken has come from the lips of certified mechanics. I am an engineer and I have worked for three different automobile manufacturers during my career and I will say this, there is never a case where a 10W-40 oil is appropriate for an older but otherwise healthy engine designed for 5W-20. Can't say it any plainer than that.

MQAcuraEL

What you are guessing at is the health of the engine. I assume the mechanic made the change for a reason. You want to assume he is an idiot. The car has been running for two years with 10-40. Another poster has confirmed he uses the same without ill effect.
What is the big negative in using 10w-40 in a hot climate?.

shipo

The negative, even in hot climates, is 0W-20 and 5W-20 are going to have flow volume benefits following a cold start versus 10W-40.

Flipping the question back to you, what would be the big negative in using a 0W-20 in an engine designed for an oil of that weight?

MQAcuraEL

This kind of thing has been discussed all over the place. For optimum gas mileage go with what is in your manual. Using 10w40 will not harm the engine, but if the guy wants to change it there is nothing stopping him.

It Wasn't Me

https://www.bobistheoilguy.com/motor-oil-101/

Enjoy

shipo

And yet evidence clearly shows cold starts, even in warm climates, cause more engine wear when running 10W-40 vs 5W-20.

MQAcuraEL

Key thing is that there is oil in the engine when it starts, regardless of type. There is a heck of a difference between a cold start in Arizona vs a cold start in January in Alaska. Again 10-40 will not harm the engine.

MQAcuraEL

On the lighter side of things-- check this out. Even bacon grease won't damage an engine lol
https://jalopnik.com/turns-out-bacon...s-e-1833784266

MQAcuraEL

And one last thing, the Civic was not only sold in the US. If you look at the oil specs for the UK model ( thanks to Roadsters link) 5w30, 5w40 and 10w40 are among what the major oil companies list as spec oils for the 1.7. I very much doubt that Honda in Singapore or Brazil for example would suggest a 0w20 motor oil. However I will bet the moon they would not recommend bacon fat.

zeroptzero

10w40 in a non-synthetic oil has long been regarded as the worst viscosity out there. It has a very large viscosity spread and will use the largest amount of viscosity index improvers (VII's) to span that viscosity, VII's have no lubrication benefit, and when they break down you are left with a very poor quality oil. True group 4 and 5 synthetics can run that viscosity spread without the need for VII's but most people won't run those oils.

I'd probably run a good synthetic 5w30 or 5w20

tech8

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