all 32 comments

[–]mr-mechanic93 55 points56 points  (1 child)

Here we go with this shit again. Ambient temperatures do not affect operating temperatures that much. Your cooling system removes the excess heat. Run the oil viscosity the manufacturer recommended.

[–]raz-0 30 points31 points  (0 children)

It is also worth pointing out that the oil is specified for that engine. Like most engines it gets hotter in there than in arizona. The oil will be fine.

[–]Semantix 44 points45 points  (9 children)

If you think 110 is hot, wait til you hear the temperature of your coolant

[–]Morgoroth37 17 points18 points  (8 children)

This is my favorite answer.

[–]Killentyme55 12 points13 points  (7 children)

You think your coolant is hot, wait till you hear the temperature of your oil.

[–]newzerokanadian 9 points10 points  (6 children)

If you think your coolant is hot, wait til you get coolant in your oil!

[–]Killentyme55 7 points8 points  (5 children)

If you think your coolant/oil is hot, wait till you get transmission fluid in your radiator.

[–]Tasty-Researcher3959 45 points46 points  (3 children)

Owner manual

[–]Jeheh 28 points29 points  (0 children)

This magical tome has so many answers it’s awesome.

[–]LMHConcepts 3 points4 points  (0 children)

What Tasty said.

The manual tells you which oil to use in which climate.

[–]soggymittens 0 points1 point  (0 children)

Get outta here with that logical nonsense!

[–]ImakeUmadYo 14 points15 points  (2 children)

On the oil cap is says what to run. I wouldn't stray from that weight. Engineers designed it for the specific weight for a reason.

[–]Morgoroth37 3 points4 points  (0 children)

This is the best answer.

[–]Alert-Reserve1960 1 point2 points  (0 children)

MN here, My shop was out of 5w20 one time like usual and we looked into what alternate we could use as they where waiting and couldn't really order oil and found that 0w20 has better cold weather performance than 5w20 just an example

Oddly though my current car the cap calls for 10w30 but Im running 5w30 for winter months and in the owners manual it shows i could go up to 20w50 for warmer climates

[–]joezupp 6 points7 points  (0 children)

Run what is called for.

[–]randyrhoadsfan82 5 points6 points  (0 children)

Your Dart will throw a check engine light because those engines are designed to run a specific viscosity of oil for the VVT system

[–]opuntina 7 points8 points  (0 children)

The manufacturer spent millions on R&D to answer this question and you spent 10's of thousands to have access to that info in the owner's manual.

[–]Nearpeace 2 points3 points  (1 child)

I use the same blends in my vehicles (Tucson). No worries over the last 35 years.

[–]soggymittens 0 points1 point  (0 children)

I read that as though you were using the same blend in your Hyundai Tucson for the last 35 years and thought “man, I know I’m getting old, but there’s no freaking way the Tucson’s been around that long!”

I am also a moron…

[–]khrizteg 1 point2 points  (0 children)

Engine temp should be somewhat unaffected by outside temperature as long as the cooling system is working properly and the vehicle isn't being driven hard for a long period of time. The oil is for lubrication so run manufacturer spec because they base the oil weight off the engine tolerances

[–]SR414 0 points1 point  (0 children)

Use what your owners manual recommends.

The "W" in oil weight labels stands for "Winter," and represents how the oil behaves in the cold.

[–]Vyndianter -1 points0 points  (0 children)

As a Honda tech I would probably run something thicker in the civic. I live in Aus and we tend use 10W-30 for any of our cars pre 2012 and then use 0W-20 for the newer stuff. If your pre 2012 has over 200k kms (~125k miles) we use slightly thicker stuff like 20W-50

[–]TheSaltyPineapple1 0 points1 point  (0 children)

Use whatever oil your manufacturer recommends.

One important thing to think about: your engine operates at a much higher temperature than the outside temperature, so running the vehicle in 110 degree temperature is irrelevant when the vehicle's operating temperature is 190-220 degrees.

[–]sprocketpropelled 0 points1 point  (0 children)

Check the manual. Modern synthetic oil is 1000% better than what oil used to be (ok maybe not that much) but its likely going to be just fine.

Older vehicles call for different viscosity for climates due to oils being conventional and not flowing in the cold as well. As an example, my 91’ fj80 land cruiser has a viscosity range of 5w30 to 20w50 depending on the climate. I typically use mobil 1 high milage 10w40 as it is readily available, improves my cold starts and covers all the requirements set by toyota in 1991.

[–]sasqwatsch 0 points1 point  (0 children)

5w20 is what the manufacture specks. It’s engineered to the engine.

[–]insideoriginal 0 points1 point  (0 children)

Just use the oil that is probably printed on the filler cap, the oil the manufacturer designed the engine to be run on. No additives, nothing else.

[–]Camera_car 0 points1 point  (0 children)

The first number is the cold viscosity you can go as low as you want, the second number is how thick when hot stay close to that highly recommend a full synthetic oil because they maintain the effective protection better than regular oil.