New (to me) Prius Questions

Please let us know how things turn out. Of course the problem will now hopefully be is what caused your dramatic improvement in mpg.

John (Britprius)

 

102,000 the ICE is close to a tune up, new plugs etc. my car is new and put 4 people in it and did a 200 mile road trip. Only got 44 MPG on that trip

 

John. You are right... I was just speaking from my experience with my '07. When I tested it, it did not drop to 10.9 it stayed around 11.9, and that was with the HID's... Unless the OP has a failing inverter, dragging rear brakes, failing wheel bearing...

 

My calculations go like this:-
Ignition on load with HID's = 20 amps (measured)
The OP stated front and rear demisters.
Rear demister estimated at 20 amps (supplied by 40 amp fuse)
Front demister estimated at 30 amps (PTC heaters on engine cold not run, 15 amps each supplied by 30 amp fuse each)
Fan motor on full estimated 6 to 8 amps.
Because rear demist on the heated mirrors will be on estimated 2 amps each = 4 amps

Total 80 to 82 amps.

I believe these figures to be conservative given the fuse ratings so that the figures could be higher.

John (Britprius)

 

Wow you are an effective person. I would have procrastinated for at least 6 months, if not life of vehicle. Important, do not be upset by the first tankful or two. Apparently the system takes a few tanks to recalibrate after the new battery.

 

Also, from what I've read, new tires, even LRR ones, tend to give you slightly worse mileage at first and then improve over time.

 

#1 rule in troubleshooting a problem (what I do for a living, with code), only make one major change at a time. Hold off on the tires until you get a few tanks in it with the new battery and plugs.

 

Glad to hear the changes seem to be helping you. You may see more improvement once the tires are broke in.

It might be a good idea to do a wheel alignment. Better for the new tires plus bad alignments also cause MPG to fall.

Good luck to you.

 

Could be the toe-in specs. Do you have the print out report?

 

They look to be well within specs and almost dead straight.
a negative (-) toe means the wheels are pointing outward.
positive (+) is inward.

Give it probably some time for you to accustomize yourself to the new tires and settings. New tires still have tall treads on them which make it a bit fiddly. Once they've been broken in, they'll be more stable.

Or maybe you're right. It's probably just crosswinds you encountered on the highway. But if you use the highway often, you may want to try and have it changed to a slightly positive toe where it gives you more straight line stability.

Another way to improve it is to upgrade the mid-chassis brace to the stiffer kind as what many have done with great results.

In my current setup, I no longer feel crosswinds on the highway. It progressively went away as I upgraded little by little. The cheapest being alignment and the under chassis brace.

My current toe is +0.4mm and it made a huge straightline difference after coming from a -1.7mm. Although it sacrificed my turn ins a bit. It feels not as sharp as before. I might dial it down back to a negative next chance I get as I only use the highway only 15-20% of the time.

 

I am happy to hear about the improvement in your mileage! Your new tires are going to impact mileage for the next few thousand miles. Once they settle in, you will see another improvement. I used to keep my 07 at 42psi front and 40psi rear. That will also help with the MPG's. Good luck and enjoy!