2003 Prius Owners

[autism360]

Hi, I bought my 2003 Prius used with 115k miles on it in April,the little battery went right away and I have had no other problems.
I am only getting about 40-44 mpg and was wondering if that is normal for the older Prius models 2001-2003
I was also wondering if I can expect any increase in mpg if I change the spark plugs and what oil and plugs are recommended.

[Rokeby]

autism360,

to PriusChat.

There are a number of factors that frequently result in sub-50 MPGs. These include:
* low tire pressure, 44f/42r or 42f/40r gets better MPGs
* majority of travel at 75 MPH and up will result in FE like you have
* lots of crawling around town at less than 20 MPH
* too much travel EV mode if you have an EV mode switch
* too much stop and start; it's better to drive like you don't have
brakes
* heavy use of the air conditioning
* oversize tires and/or rims
* some replacement tires can result in a 5 MPG loss

Lots of threads here on how to get max MPGs. Use the search tool to find 'em.

I'll leave comments on plugs and oil to those that know.

BTW, are you doing oil changes and tire rotation at the recommended 5K mile interval?

Hope this helps

[tochatihu]

Hi the spark plugs are iridium - two acceptable versions made by denso and NGK. There are no known substitutes that will offer the improvements you seek. If the plugs have not been replaced, now would be a good time.

I think that Rokeby's suggestions will help a lot. Adding: remove unnecessary cargo from the car (if any) and make sure the engine oil is not overfilled.

Skip the part about the EV switch. You don't have it.

I do (did) use 0W20 synthetic oil in 2001 Prius but the effect on mpg is quite small.

As you are new in town (hi) let me also suggest that you consider changing the transaxle fluid. There have been several Prius Chat discussions about that.

[autism360]

Thanks Rocheby and Tochatihu for the fast response. I live in Az so a/c is a must. I will check the tire pressure and replace the plugs and see if that improves my mpg.

[tochatihu]

By the way, if you give the VIN to a Toyota shop they ought to be able to provide you a complete history of service (performed by toyota shops) that is is always useful info for 'downstream owners'.

[autism360]

My 2003 Prius stalled and would not restart after driving about 1/8 of a mile a few weeks back, the dealer charged me 1300.00 for a new computer, yesterday the same thing happened with the exact same symptoms and I had it towed again to the dealership. Anyone have any ideas what could be causing this?

[Rokeby]

autism360,

As a minimum, the techno-gurus/troubleshooters here will want to know:
* What if any warning/alarm lights were lit on the dash?
* What if any trouble codes were "pulled" or retrieved by the dealer the
first time this happened.
* In an earlier post you said, "...the little battery went right away..."
Does this mean you put in a new one? Toyota or another brand?

Hang on, one of the techno members will most likely weigh in soon.

From that earlier post; Have you seen any improvement in your FE/MPGs?

[autism360]

Hi my Prius died again, the check engine light came on with the brake light and the car died about an 1/8 mile after start up. The small battery was replaced with an oem battery 2 months ago and the plugs were changed about 2 months ago as well with oem plugs.
car dies less than 1/8 after startup with check engine and brake light coming on.
The first time the dealer replaced the computer 1200.00,the last time all they could find was a blown efi fuse and it is in the shop now for a 3rd time?

[tochatihu]

Make sure those ignitor (plug) connections are clean and seated well. Fuel injector wires too. All I've got.

[autism360]

They finally think they found the problem it was a wire that was in the corner under the dash that had a bare wire that was hitting the metal and blowing the EFI fuse.I cannot help but wonder if the 1400 it cost me to have the computer replaced was a total rip off since the exact same symptoms happened all 3 times my car died.