horrible mpg, and frothy oil

Not sure if the 2 are related, but anways, I could use some help.

I just bought the truck a month ago, and I wasn't sure about when the oil needed changed, but the light came on yesterday, so I changed it today and put in Mobil synthetic 10w30.
Anywho... when I drained the oil, there was alot of frothy bubbles on the drain plug. I went ahead and added new oil, and after I got 5 quarts in, I fired it up for about 5 minutes just to see where the level was at so I didn't overfill. After shutting it off, I pulled the dipstick out and there were those frothy bubbles again.

I may just be anal, but in my car, frothy bubbles is a blown headgasket. I doubt I have a problem that serious, but just curious what you all think.

As for mpg... I used over 1/4 of a tank today going less than 70 miles... most of which was interstate at 60-70mph. I'm no mathematician but that equals out to LESS than 280 miles to a tank... which is like 13 mpg. I do have a cold air intake, but I drive as much under 2000 rpms as I can, and I still do terrible.

Thoughts???

 

What year Tacoma did you get? I have a 2006 and I'm pretty sure all 2nd generations take 5W 30 instead of 10W 30. I know that has nothing to do with the bubbles but just some info for you. I also get pretty poor gas mileage but that was after my 3" lift and 33"s. I also have a TRD CAI and a Flowmaster cat-back exhaust system.

 

not too sure about the frothy bubbles but keep an eye on it and the gas mileage youre getting is about the same as mine since bigger tires and lift + winter gas

 

As far as "frothy bubbles", when you took the oil cap off, was there a beige looking residue on the cap? This type of frothy bubbles just means there is slight moisture in the oil. This is a very common occurrence in colder areas. Nothing to be worried about. Although the weird thing is that you would not have this froth on the drain plug. If it is there, then all the oil should be frothy. The only place you would see this is on the cap and maybe on the dipstick.

And for future reference, even though synthetics hold to their viscosities better than conventional oil, it is best to use a thinner oil like 5W30 in the winter. The colder it gets, the thicker the oil will be to pump at startup and when cold.

 

There has been a lot of frothy oil threads lately. Concensus has been that it is due to a lot of short trips, and the cold. I would suspect that the winter gas is not helping your mpg's either. My gas mileage stinks as well, I can't get over 17.

 

There have been a lot of creamy oil at the filler neck threads- If you are getting froth in the bottom end you need to get that shit looked at or at least get the oil analyzed.

Is this terrible MPG recent or it's been happening since you bought the truck??

 

Geez, I can't believe myself sometimes. The cap says right on it 5w30, and what do I do... get the wrong stuff.
Well I guess at least I'm not the only one with frothy oil, so I'll stop worrying about it then. I did try and search 'frothy' and 'bubbles' and didn't come up with any threads, so I figured I was one of few with the problem.
The mpg thing really bugs me. I'm getting the mileage of a v8 with a v6, and I baby the throttle. I don't have a lift, or bigger tires... I hope it gets better.

 

The oil plug had bigger bubbles on it, not quite froth. What would that mean???

When I bought the truck I had to drive it home from Vegas, and I averaged 16mpg. Its weird to say, but it seems my mileage is getting worse by the day. I just can't really pinpoint the issue? I did buy a stock intake from a kid on here... I'm going to throw that on and see what happens as soon as I get it in the mail.

 

I would switch back to 5W30, thicker oil usually makes the engine run harder and using up more gas. You'll be good again

- Rich

 

I have religiously changed my oil every 5k, and never had any type of bubbles/froth. But this last time I slacked off and waited till like 8k and sure enough there was froth when I drained it. The old oil just had more time to break down and add more contaminants over time. I have always run full synthetic.

So chances are, since it sounds like you bought it pre-owned, it had prob been a while since the oil was changed. And as far as the mpg goes, the main mpg robber for me is always a dirty air filter. I will notice a 2mpg gain consistently after I change the filter out. Did you clean/ replace it when you did the oil change?

I don't think 10w30 instead of 5w30 would have too much affect on mpg, but you never know. If you are concerned about, I would just switch it back.

 

Also, the only way to accurately measure mpgs is to top off your tank, set the trip meter, then when you fill up again, divide the miles you drove by the gallons it takes to top it off again. You can never really trust the gas gauge to tell you exactly how many gallons are in the tank.

 

Use 5W-30

Clean the throttle body

Clean the Mass Air Flow sensor with the special CRC MAF cleaner

Change you plugs

After doing this you should see your MPG's go up

 

Lose the CAI, all it does is suck gas and lose low end torque.

 

Some good quality pictures of what you are seeing would be helpful.

Use the right oil. Oil viscosity will have a mileage impact.

Air filter MPG increase on a modern, fuel injected engine is a myth. Proved in the lab. The fact that this type of marketing is still out there and used to sell filters when it is not scientifically sound really grinds my gears.

 

The intake was on the truck when I bought it, I bought a stock intake last week from a guy on here, I hope he sent it...

I'll clean out the tb and sensor this weekend. I'll search the best plugs to use, and throw a new set in, see what happens.

I'm really mad I spend $50 on the wrong oil. I'll probably wait a couple weeks to change that, get a little use out of it anyways.

 

So I found out my mpg problem.

Basically I let the fuel gauge hit empty for the first time. It was about a tick away from the red mark when I filled it... it took 15.7 gallons and was on full. So where the hell is that other 5 gallons going? I'm gonna be TICKED if the fuel gauge reads that inaccurately.

Maybe my cheapo rear leaf springs are sagged so badly all the fuel is at the back of the tank... that would just be awesome.

 

That is weird! Wish I had an idea but I don't.
Mine is about down to 1/4 right now, I will let it get down to the red just to see how many gallons it takes cause now I am curious.

Oh and as far as plugs go I think if you search on here everyone pretty much recommends going to the dealership and getting the stock Denso plugs.

 

Yeah, I'm curious if other people have the same issue. I did see a few threads about the fuel gauge reading fairly inaccurately due to the shape of the gas tank... but what I'm experiencing is a little too outrageous. I mean I can seriously watch the gauge going down as I drive in grandpa mode... at least I do know that my mpg isn't as bad as I thought it was, but a fuel gauge being this inaccurate is something I'd expect on an old truck, not a new one.

 

I think when the low fuel light comes on, you have about 4 more gallons of fuel left.

 

Just for reference I calculated my true mpg today, and its just a hair over 15 driving normally in town.