SC400 95. Stock. 124k Miles

I am the 3rd owner of this car. I have no idea how the first owner treated the car. I do have contact with the 2nd owner he told me only filled it up with premium 2 times a month >.<. Well iv been filling it up with premium since I got it couple months ago. Anyways I put 35 dollars in the other day and I noticed I only got 140 miles from the trip timers wtf! Now I don't drive crazy but don't drive the smoothest so somewhere in between. What is something I can do to increase my mpg cause this is insane I can't be filling up 35 dollars worth for almost 140 miles

Suggest so far been a new air filter, and a tune up is their anything else I can do. Or pour something into my engine to clean out the I guess it be called sludge build up from the regular gas that was used.

 

How about changing out the fuel filter, changing the oil, and do the spark plugs. Relatively cheap maintenance items.

 

K ill try that ty.

 

The way you are calculating it you really have NO idea what your real mileage is. If the gas prices change between the lst time you filled up and now, it will affect your readings. Get an accurate measurement of your mileage 1st. You really have no idea where you're at. Fill the tank, note the miles traveled, divide the miles by gallon then reset the trip odometer and when you fill up. Do this 2-3 times before you come up with a conclusion.

Make sure you have proper air in your tires, and keep the car running right. Just follow the maintenance schedule.

Mine gets consistent 22-23 MPG with 50% highway use on super. If you have your foot in it I can see it going down that low.

 

doesn't lucasoil make a whole bunch of fuel treatment products and sludge eliminators http://www.lucasoil.com/products/dis...?iid=5&catid=6

 

I don't know about anyone...but is it normal for the fuel gauge to drop down when the engine has just been started, say in the morning?

 

^hmmm i don't think that's normal...my gas needle on my old cluster stays exactly where it was the night before even during winter time...but my new cluster is pretty weird. It would go to full everytime you do a cold start then it will eventually go down to the accurate level after driving couple of miles. Furthermore, the low fuel lamp doesn't turn on even though i swap a new bulb in. TO OP do what Ryeno said, but it be alot of money so hopefully you will be able to do all the work and just pay for parts.

 

that's what I meant but on cold starts, if I would drive it out of the drive way, the gauge would drop down a tiny bit...quite annoying.

technically, in 20-25 days, if I cold start my car and move it out of the driveway and park it back every single day and turn it off, the gauge would point to empty.

 

I've been reading the 'SeaFoam' thread in the Performance/Maintenance section. Seems like you'll get better overall engine performance (and I'm assuming efficiency) if you do it right, or if it really works..

 

The seafoam treatment seems really complicated to me about what hose you plug it into

 

It isn't that complicated, but I've heard that maybe the gunk in the engine is what's keeping it sealed?

 

What's more horrible is that after at least three monster threads pushing 200+ posts on MPG....... we have another. MPG threads have been around more than Jenny from the block.

 

I did seafoam and i felt a difference im not exactly sure if the mileage got better but im pretty sure it did.

The hose is your brake booster line or pvc line.

Thats what i thought also i was afraid at first but i was like eff it imma try it out. I did it and it turned out perfectly fine i was at 174k when i did it..

Ideally when you seafoam all the gunk shoots onto the spark plugs so its recommended to buy some cheap spark plugs then seafoam and change it out but getting to the spark plugs can be a PITA

 

oh thats where it goes, thanks i always wondered

 

Make sure no vacumn lines are off, any sensors unplugged MAF to throttle body hoses properly attached and clamps tight, you should be between 20- 23mpg.