Bad mpg and oil smells like gas

Have a 08 tacoma 2.7 5speed just recently change the oil about a month ago with royal purple 0-20 with toyota filter.noticed I was geting terrible mileage all of a sudden so was checking over a few things while checking oil noticed it smelled like gas and was darker than usual but not over full.i have no check engine light on and drives perfectly fine beside a very slight rough idle other than that runs like a champ.was getting around 400 miles on a tank now only getting a little over 300. heres a list of things that have been done in the last few months.

New Dealer iridium plugs gaped .043
Cleaned throttle body and put new oem gasket in old gasket had screen in bottom new one didn't dealer said it was fine
Checked and Cleaned mass air flow sensor
Checked and cleaned PVC valve
Checked and cleaned both o2 sensors
New stock style drop in air filter k&n not over oiled already check to make sure wasn't oil on mass air flow sensor
All new royal purple fluids in tranny,transfer case and front and rear diffs


Any ideals would be greatly appreciated thanks!

 

Does it smell like gas when you pull the dipstick? Or just at the valve cover when you pull the oil cap off?
You'll always get a little gas blowby at the rings when you start the engine from cold, and a small amount of gas can make a lot of oil smell bad.
Also, maybe consider going back to the recommended oil weight for your engine on the next oil change.

 

Dipstick smells like oil haven't pulled the cap and smelled in there yet.thats the oil weight recommended in my manual 0-20 or 5-20.

 

I thought that the 05-12 2.7's took 5W-30...
That's what the owners manual in my '10 specifies for the 2.7, at least.

 

My manual says 2.7 0-20 or 5-20 but for the 4.0 engine it calls for 5-30

 

I'd run some Lucas fuel system cleaner with what's left of fuel in the tank to maybe clean and free up any sticking fuel injectors then change the oil and filter. Let it drain for an hour or so. In a week or two change only the engine oil filter, again.

 

Could be the Royal Purple? I heard it wasn't a good brand for Oil.

 

How many miles between changes? I've always noticed a little gas smell in the oil on newer vehicles with long intervals. I don't let it worry me.

Also, I got caught up in the Royal Purple advertising a few years ago and switched to it from Mobil 1. The engine in my 08 GT was noticeablely louder and more coarse with the RP. Switched back to M1, quiet as a mouse again. Draw your own conclusions.

 

FWIW stick with the major brands of oil... like Mobil 1 is is always a good call

boutique oil from small houses (royal purple) guess what ? they have not spent the tens of millions doing research with the military on severe use...Mobil has...

not saying royal purple is bad, just saying why guess ?

as long as you are changing the oil regularly, almost anything is going to do just fine.

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anyhow gas in oil sounds like a stuck or bad injector dribbing gas into the cylinder on shutdown, or bad coil or bad plugs....should pop all injectors and have them bench tested. pop and inspect plugs too.

 

If it's forcing fuel into the sump there is no doubt that it would throw a code and probably would over heat the cat. All used oil has a smell to it.