Oil Viscosity and Burning

So I changed the oil in an engine that takes 5W-20 that calls for 5.5 qts. But only 2 Qts come out... no leaks.

What is the thickest engine oil you would recommend to me that won't reduce fuel efficiency that will help with the oil consumption.

5W-30
10W-30
10W-40

Maybe use the high mileage type oil.

Any oil treatment additives anyone has had any luck with. Truck has 125K miles on it

 

Was it red ? You may have drained transmission fluid (common occurance among 2gen owners)
2 qt sounds like tranny fluid, if you had 2qt in engine I am pretty sure you would have low oil pressure light on constantly. 2qt is not enough to lubricate engine

 

Nope, wasn't in a tacoma. This is a general question about oil consumption. I may have posted in the wrong section however... apologies.

 

Oh OK post in the right forum next

Also oil you seek is 5W-40
10W-30 would be your other bet but only if car can take it.

 

Thanks guys.. yeah I'm in socal so doesn't drop below 20 degrees unless up in Big Bear or Mammoth in the winter, but then I'll have my truck up there.

I'll probably go 10w-30 high mileage next oil change, until then I'll just keep my eye on it... (Wifes Car)...

Thanks all!