Question about oil change because i don't drive a lot.

Also, ‘Heavy Service’ divides that number in half (extended towing, city driving, and summer driving with 90°+ temps).

 

Don't be afraid of the manual, fluid specs, quantities / volumes, are all in there.

 

To better answer your question oil has 3 main responsibilities:
1. Lubricate
2. distribute and disperse heat
3. suspend and transport impurities to the filter.

0w20 was spec'ed for the 5.7 engine. You can use other oil viscosities but that was what toyota engineers determined to be the "best"
I say "best" because there is almost always some type of compromise. The compromise is wear protection vs efficiency.
you want the least rotational resistance while still ensuring wear protection. Maximizing efficiency will boost MPG.
All of the testing was done with 0w20 during development+ long term durability. I wouldn't stray from it.

There are dozens of oils to choose from why do people recommend mobil 1?
Mobil 1 isn't the cheapest but also isn't the most expensive oil. Think Royal Purple or Amsoil
IMO (in my opinion) there are 2 reasons: quality and availability. It is a upper level quality oil, and it is easy to find.
The independent oil testing articles i have read have shown good results from Mobil1 against competitors.
Is Amsoil better? Maybe. Can i easily and quickly pickup Amsoil at Walmart? No

Just like a swimming pool, oil has its own ideal PH level.
Over time exposure to heat, blowby gases (by-products of combustion-carbon /fuel/etc) and moisture changes the PH of oil.
The filter can remove contamination/debris/ particulates, but cannot change or adjust oil composition.
The extended life oil has special additives to help stabilize the oil for longer periods of time and minimize the oil breakdown process.

There is plenty of good/bad & correct/incorrect information on the internet about oil.
Alot of information is marketing propaganda from oil companies.
Alot of information is personal opinion based on zero facts.
Different test methods will produce different results. Keep in mind a good oil can show poor test results depending on the test methods.
Determining whether the test method mimics actual real life conditions and is truly applicable is the hard part.

 

I'm with some of the others. Every six months regardless of mileage. I would also recommend at least weekly going for a ~20 mile drive just to get your drive line to operating temperatures.

 

I agree very important to drive on the highway once a month for 30 minutes.

 

This is the way I did it when I had a 2 mile each way commute. It takes 8-10 miles of driving to get the oil temp up to steady state. A 1988 Corvette I owned back in the day had an oil temp gauge and I would watch that and count the miles to steady state.

Take the long way once a week and no need to change the recommended intervals.

Dan