2015 civic si lubricants
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andre12dbsi
Well-Known Member
I'm sure others will jump in but I tend to go with what the Honda engineers say is the best for lubricants.
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Your mileage will probably suffer using 5w40. It's definitely a heavier oil. Some go to heavier oil if they're boosted. It'll tend to help with heat/oil shearing. Is your engine stock? No turbo/supercharger? I'll tag @Bruce Bartlow to comment. He tends to know a lot on oil.
Monk
Well-Known Member
Your mechanic, like many ppl that have "Always" used a 10w30 range mix, are shy about that "0" part. and what that 0 does, is to get the oil flowing faster at cold start up...... after it starts getting warm the 20; 30; 40 part takes over the protection of the engine.
As for you, since you're not giving up what State you live in, I'll say if you live where it's cold in the winter, I'd stay with the 0 or 5..... and if it gets real hot in your State in the summer move up to a 10w40, if it's going to make you feel better(but totally not needed.....The oil flow is restricted with higher wt. oils for these modern engines).
Also, the thicker wt. oils are going to produce worse fuel mileage.
Bruce Bartlow
Late apex everything
Thanks for the question. And when tagged by none other than hello pants @webby, how can i resist.... i'm it! My friend @Monk is correct on both points. 1.) Yes, gas mileage will suffer. 2.) The higher viscosity 40W does protect the engine despite the 0 (better cold starts) part. For a while anyway...
So I add the following:
1.) The drop in gas mileage will only be evident at progressively higher RPM's. 3,000 is big, or about 70/75mph depending on gear ratio. Has something to do with the mathematics of internal fluid friction. I also suspect it has something to do with how Honda designs the engines... as a general rule these are family cars but often given an 'attitude' for more power over 3,000RPM. VTEC kicks in, at various stages over 3,000.... with the biggest VTEC burst at around 5,000 although depends on the car. Anyway, look up the "Reynolds equation" for more details (which is below).... but only if you want your eyes to glaze over.
Bottom line? You wouldn't notice much reduction in fuel mileage in typical around town driving. In freeway driving you will.
2.) About viscosity? Surprisingly even 20W oils protect well, often just as well as 30W oils. I didn't believe it myself until I saw test results. 40W+ oils are meant for cars really pushing the performance envelope. 60W is a racing oil. A subject for another day.
Anyway, I tend to prefer lubricants with tight viscosity bands like 5-20 or 10-30 (rather than 0-40, for example) as the viscosity modifiers (chemically very light) needed to construct those versatile viscosity bands are the first components to deteriorate and burn off as the oil breaks down. That means all that's left is the base oil, not the big bad multi-vis 30W or 40W when you bought it. The 30W or 40W is gone. When all the viscosity modifiers are gone -- you're left with nothing but the lighter base oil.... which is not the best protection.
In case you're wondering, here's that Reynolds equation:
Now, aren't you glad you're out of school?
So I add the following:
1.) The drop in gas mileage will only be evident at progressively higher RPM's. 3,000 is big, or about 70/75mph depending on gear ratio. Has something to do with the mathematics of internal fluid friction. I also suspect it has something to do with how Honda designs the engines... as a general rule these are family cars but often given an 'attitude' for more power over 3,000RPM. VTEC kicks in, at various stages over 3,000.... with the biggest VTEC burst at around 5,000 although depends on the car. Anyway, look up the "Reynolds equation" for more details (which is below).... but only if you want your eyes to glaze over.
Bottom line? You wouldn't notice much reduction in fuel mileage in typical around town driving. In freeway driving you will.
2.) About viscosity? Surprisingly even 20W oils protect well, often just as well as 30W oils. I didn't believe it myself until I saw test results. 40W+ oils are meant for cars really pushing the performance envelope. 60W is a racing oil. A subject for another day.
Anyway, I tend to prefer lubricants with tight viscosity bands like 5-20 or 10-30 (rather than 0-40, for example) as the viscosity modifiers (chemically very light) needed to construct those versatile viscosity bands are the first components to deteriorate and burn off as the oil breaks down. That means all that's left is the base oil, not the big bad multi-vis 30W or 40W when you bought it. The 30W or 40W is gone. When all the viscosity modifiers are gone -- you're left with nothing but the lighter base oil.... which is not the best protection.
In case you're wondering, here's that Reynolds equation:
Now, aren't you glad you're out of school?
Monk
Well-Known Member
I like the part about keeping the bands close......
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lol and there you have it. Thanks bruce
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Dennis Rockholt
9k Alll Day
www.bobistheoilguy.com/
There is a lot of information regarding viscosity and different oil weights on this website as well.
There is a lot of information regarding viscosity and different oil weights on this website as well.
Bruce Bartlow
Late apex everything
_______________
And @Dennis Rockholt and I agree most with the Honda engineers who are building the new Type R.
Bruce Bartlow
Late apex everything
______________
Typical. A 5 cent question with a 50 cent answer.
Dennis Rockholt
9k Alll Day
haha yeah that type R, if it is in the states next year or this fall, I will be making that happen. Someway, somehow.
Bruce Bartlow
Late apex everything
________________
Yep... you'd be the second guy to get one! lol... just kidding. The first batch will probably be 5,000+ over full sticker. I could never do that.
... quick question @Dennis Rockholt: For the Civic, what kind of HID headlights do you like? Mine need replacing anyway (rock damage) so might as well make them nice.
Dennis Rockholt
9k Alll Day
Uhm I would just use HID depot or whoever the vendor is on here....I purchased some from them and they are great quality. 8k was what I got, and they are great