DrewO

Hello all,

is there anyway to help rectify why my scion 2004 xB is getting only 200 miles with a full tank of 93 premium. I have used additives in the gas. Any guidance would be greatly appreciated

MileHightC

What else have you done besides additives, which typically don't do anything. I'd start with looking at basic routine maintenance items and go from there.

2stroked

First of all, premium (93 octane) does absolutely nothing for the performance of your xB. Yes, it may make you feel better, but it does nothing to enhance performance or mileage. Also remember that when you have additives in your fuel, you will generally get fewer MPG. Try a full tank of unadulterated regular (87 octane) and see what that does.

Second, as has already been stated, check the basics first. Jack the car up and see if you have any brakes dragging or wheel bearings going bad. Check and if needed, replace the air filter. Then get back to us with what you find.

OMGABOX

How fast are you going? Anything over 65mph and you’ll get worse and worse mpg. Other factors include how much weight you’re hauling, your wheel size and weight, your tire pressure, having a roof rack, etc. Also what other people said, premium fuel has no positive effect for our econoboxes so save yourself a few bucks and stick with 87 octane.

drizzoh

An xB should be getting much better than 16mpg.. that's what my lifted Tacoma gets lol.

You have good coils and plugs? No vacuum or fuel system leaks? Good alignment, tires and proper psi?

Also that engine does not need high octane. Without a tune for it, it's actually hurting your performance and mpg.

DannoXYZ

1. Measure fuel-pressure in rail. There's a regulator somewhere that may not be functioning properly.

2. Also test with disconnecting O2-sensor. Bad sensor will continually tell ECU that mixtures are LEAN and ECU will try to increase fuel. Then check O2-sensor and find it's reporting LEAN. So it tries injecting even more fuel while O2-sensor keeps on telling it mixtures are LEAN no matter how much more fuel ECU tries to inject.

3. measure TPS output. If it's sending out WOT throttle signal when you're only at 25%, then ECU will end up injecting way, way too much fuel.

4. are brakes dragging? Jack up each corner and spin wheels by hand.

MysticPanda

I know the answer to this question!!! Back in June the government started watering down our gas supply by putting (20% I believe by my calculations) more ethanol (making it a total of 30%), causing MPG's to drop significantly. This was how they could artificially lower the gas prices for mid-term elections and also begin to make the push towards EV's. Most vehicles are NOT made to handle more than 15% ethanol, making this move a direct attack from the powers that be to ruin our vehicles and attempt to force us into EV's. California has already passed law (I believe) to do away with regular gas powered cars by like 2035. The added ethanol will cause things like rough idling, mucking up our spark plugs, plugging up our fuel filters, etc. I started using a product called Govvi that was showing immediate success in cleaning the engine and giving an MPG boost, much like the stuff you pour into your gas tank but in tablet form. They released it in June and it was about then that the added ethanol started showing up. My van went from 19 mpg around town to 15. I lost about 65 miles for a whole tank of gas. So at this point, I'm continuing to use the Govvi mainly because it's a protection against the added ethanol. It is not your vehicle.

RichBinAZ

Mystic Panda. The government is not out to get you. Take off the foil hat.
See if your state produces data about fuel quality like Arizona does
See this example https://ctutools.azda.gov/dwm/pv/Ins...sp?idno=328780
If that page doesn't work, start here, https://ctutools.azda.gov/dwm/pv/inspection_search.asp , put in Mesa for the city, select fuel quality from the drop down and pick one of the numbers from a fuel station you recognize.
There is a lot of info there. I believe ETOH is ethanol (8.7% in regular, 10.3% in premium), RON & MON are octane numbers and they sometimes drop, resulting in unexpected engine ping.

If Indiana doesn't produce this data, you should complain to "them". I bet they are checking for "fuel quality", but do not publicly post the results. Ask them where they are hiding the data.