Hello, scion people!

I am new to the forum thing, and a relatively new scion owner. That is to say, my husband and I bought a RS 1.0(manual) in May.We love it, but the mpg that was awesome at first has fallen within the last month from 32(avg city/hwy) to 27 or so, and appears to be steadily declining.And, the power(what there was) has taken a hit as well.AAARRGGGGHHHH! We have not changed out driving, but we have changed the oil and the spark plugs.Plugs are NGK platinums. What am I doing wrong/missing?I put a injector cleaner in as well when we first noticed the drop, and it didn't help. Anyone else have this problem? Btw, car has only 45,000 miles. Any input would be appreciated.

 

Check the air filter. It can easily rob you of horsepower and kill your gas mileage. Check your tire pressure as well.

Also, did you mileage drop after you changed the oil/plugs?

 

Yes, tire pressure is fine, a little above what it should be. Air filter is new as of june/july-it is on the AEM CAI.Mileage continued to drop after the oil/plugs. It wouldnt be a big deal, but we bought the car for the mpg(plus it is Hot Lava, too cool to pass up). And if I had more money I would take it somewhere to get it checked out...

 

That would be my first suggestion too.
Also, changes in the weather tend to affect it as well.

 

I noticed a slight decline in mine after switching to NGK Iridiums (which was the opposite of what I expected.)

 

My MPG has dropped like a rock since the weather cooled down. I'll be really happy if i get 35mpg this tank. In early september/late august, I was regularly getting 37-39mpg. I'm not doing anything different, it's just the cold, damp weather.

Wet roads seem to kill my ability to coast, too, which clearly means rolling resistance is up, as nonsensical as that sounds.

 

weather and the gas company might of switched to their winter blend fuels

 

it would also help to unhook the battery for 30 sec or so to reset the ecm. it will reset the long term fuel trim!

 

Thanks for your input!mpg first started going down when we were driving in the rain for two days straight, maybe that has something to do with it.Anybody ever have eny proplems with the fuel pump/filter?( In case resetting the battery doesnt help.)Went to autozone to find out how much a filter costs only to find that you cant replace it by itself.Drat.

 

The fuel filter can be replaced by yourself, but it's a real pain. You shouldn't need a new filter though.

 

Autozone said fuel pump and filter had to be changed together.I really need a service manual.That would be helpful.I want more power in the xb(but im too poor)!My 69 bug is faster.

 

Autozone wants to sell you a $164 fuel pump.

A repair manual can be found online:
http://www.myjdmphoenix.com/images/04_xB_Repair_Manual/

The fuel pump seems fairly easy to do, just expensive, and it's not a wear item, per se.

Winter gas blends, as was already mentioned, easily cause a hit of several mpg.

The autozone site, interestingly, sells the fuel filter for $21, in the off chance that's the problem.

My vote is still winter gas + weather changes.

 

yes this problem happens every year

 

Check my signature. I have a factory service manual there.

 

Thanks guys! Will check out the manual.Will chalk it up to winter gas blend for now, hope it improves in the spring...-

 

You seem to have done all the things that kill my mileage: oil/filter, plugs, air filter, fuel injector cleaner. The xB is picky and mileage does drop off around 4500 miles after an oil change. Seems much happier with the new oil, plugs and filter.

Here are some things that came to mind..

Did you gap the plugs?

What type of oil are you using?

If you aren't already switch to synthetic - I was gaining 2mpg around 6000 miles after I did it. Do the first change at about 4500-5000 miles to get out the gunk then run the new synthetic till about 7500 but change the filter at 3500 and top off the oil.

The filter for the fuel pump is around $40 and can be done seperate somebody had a nice write up with pictures, there are two filters and they are attached to the pump which is inside the fuel tank. I don't belive that is your problem though I have 211,000+ on my box and fuel flow is not an issue I get 34+ mpg almost all the time.

I also have some tips here for keeping your car happy.. http://www.365motorwerks.com/news.aspx

And if you haven't already check out the ScanGaugeII (link in my sig) it helps give you some good info about what your right foot is up to!

 

I agree with the colder weather and gas. A quick Google search found a post saying winter gas started shipping in mid September. Don't know if it's true or not, but that corresponds with the timing of your mileage drop. If you consistently fill up at the same gas station or with the same brand, try another and see if things improve. My experience has been that Shell performs best, Sunoco performs worst, the rest of the brands fall somewhere in between.

The xB takes longer to warm up than other vehicles I've owned. Last week when we had some 30 degree mornings, it took 15+ minutes in stop and go traffic to get to normal temp (184 degrees indicated on the ScanGauge). In the meantime, it's idling high and burning more gas.

Make sure you use light weight oil. Don't use thicker than the specified 5w-30.

 

When my B was stock, I was getting 33-34. Now with intake/exhaust, it dropped down to 28-29. Same driving habbits and all, change gears at 3k rpm, drive 60 on freeway(speedlimit).

 

I do believe it's to blame for the winter gas.

Remember, gas prices started dropping after the bailout plan passed, the gas companies probably pushed their lower grade winter gas early so they could easily drop their prices without taking a big hit.

 

The drop in gas prices is NOT because the bail out plan passed. The prices went down because the price per barrel dropped dramatically. I.E sub $100/barrel. I've noticed a slight drop in mpg as well but my driving changed a little bit and if you read a gas pump, at least around here. It says "RVP June 1 - Sept 15 or 30th" I can't remember the exact end date but we've been "on winter gas" for a while now. I have a scangaugeII and it is by far the best investment I have made. Help numerous friends with CELs diagnose their cars. Also being able to monitor most of what goes on while I drive is cool too.