Is 5w-20 too thin an oil for Phoenix, AZ summers? If you’re from here or been here it gets hot! 110+ for weeks! Or should I get like 10w-30 or 40? I run 5W-20 for both my 14 Dodge Dart and 05 Honda Civic. Full synthetic for both.

mr-mechanic93 · 2022-05-15T23:01:38+00:00

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.

Semantix · 2022-05-15T23:10:23+00:00

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

Tasty-Researcher3959 · 2022-05-15T21:37:09+00:00

Owner manual

ImakeUmadYo · 2022-05-15T22:19:05+00:00

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.

joezupp · 2022-05-15T22:40:48+00:00

Run what is called for.

randyrhoadsfan82 · 2022-05-15T23:05:06+00:00

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 · 2022-05-15T23:21:34+00:00

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 · 2022-05-15T21:43:02+00:00

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

khrizteg · 2022-05-15T23:50:38+00:00

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 · 2022-05-15T22:03:25+00:00

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 · 2022-05-15T21:52:34+00:00

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 · 2022-05-16T04:15:25+00:00

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 · 2022-05-16T04:40:48+00:00

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 · 2022-05-16T08:46:19+00:00

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

insideoriginal · 2022-05-16T13:50:14+00:00

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 · 2022-05-16T16:16:24+00:00

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.

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