Prius ICE starts after only a few seconds - Gets only 41 MPG

[Cd]

My dads' 2008 Prius' ICE starts after only a few seconds.
He starts in electric, and get around 10 feet before the ICE kicks on.
On a recent trip from Houston to Austin, the car struggled to do 41 MPG.
This was at a smooth 70 MPH and with the A/C set to low.
Tires at " factory 35 / 33 psi "

Surely the car can do better, and I'm wondering if there is some technique he should be using to keep that ICE from coming on so much.

Is the ICE coming on so much a sign of battery problems ?

While we are at it, he is wondering if there is a way to shut off the annoying backup beep.

- Thanks

[Isaac Zachary]

Originally Posted by Cd

My dads' 2008 Prius' ICE starts after only a few seconds.
He starts in electric, and get around 10 feet before the ICE kicks on.
On a recent trip from Houston to Austin, the car struggled to do 41 MPG.
This was at a smooth 70 MPH and with the A/C set to low.
Tires at " factory 35 / 33 psi "

Surely the car can do better, and I'm wondering if there is some technique he should be using to keep that ICE from coming on so much.

Is the ICE coming on so much a sign of battery problems ?

While we are at it, he is wondering if there is a way to shut off the annoying backup beep.

- Thanks

Sounds kind of normal to me for a cold start. Unless you modify the hybrid system the engine will always start up a few seconds after turning on the car in order to warm up the engine and catalytic converter.

After that, if everything is warmed up to normal then you can keep stopped without the engine idling.

An old battery will have the enigne come on more often. A 2008 Prius will be needing a new battery sometime soon, maybe next week or in a few years from now.

But the best way to save fuel is to just pulse and glide. In other words don't rely on the electric motor since essentially that electric energy comes from the ICE anyway. By maximizing the ICE's efficiency by accelerating with the accelerator pedal closer to the floor, but not floored, you can then let off, and if the engine and all is warmed up the ICE will turn off at speeds under 35mph or so. You can even slap the shifter into N and let it coast down some 5 or 10mph or so and then shift back into D and speed back up again.

Also coast to stops as much as possible from a long way back so as to not use a lot of regen braking and definitely as little friction braking as possible.

Driving around in an "EV" mode in a 2nd gen Prius doesn't help unless you have a bigger battery and a way to charge it modded into the car as a plug-in hybrid mod.

Unless you're using up the battery before parking for the night. That way in the morning your engine will be doing more than just warming up, it will be charging the battery too. To do so determine how far from the house you need to do this (about a mile or so) and then just be really easy on the accelerator pedal and drive around at like 25mph or less and watch your charge meter. The goal is to have just two bars once you get home.

[rmay635703]

Cold weather short trips and a weak traction battery will do that.

[jakobnev]

This is how it was designed to work:

Whats Going On As I Drive?

Did he recently get it or has he had it a long time and the car changed while he had it?

41 MPG? Maybe someone put cheap high rolling resistance tires on it?

[Vman455]

The engine will come on a few seconds after turning the car on, that's normal. It will auto-shutoff only when the coolant has reached a certain temperature (101F on 2010-2015; I don't know what the exact temperature is on a 2008, but it's probably around there).

Depending on weather conditions, and especially wind, 41 mpg at 70 mph is normal. I drive 50+ miles in opposing directions two days a week and the difference out and back, depending on wind, is sometimes more than 10 mpg. One trip doesn't really tell you anything about the car's or battery's health.

[TexasCotton]

A couple of cycles are triggered when you initially start a Gen 2 Prius 04-09 year. The vehicle will likely attempt to do these cycles.

Maintain 12 Volt Aux battery around 12 -13 volt battery and recharge during warm up

Run until a O2 sensor heater reaches a pre set temp .

Recharge traction battery if too low of SOC

If the above thresholds are not met... the vehicle is going to have OBD codes that should be checked

Current ambient temperature has effects additionally ....dead of winter like a Texas February longer vehicle warm up time... Peak of Texas summer 90F plus vehicle shut down fast for ICE.

[Cd]

Originally Posted by jakobnev

This is how it was designed to work:

Whats Going On As I Drive?

Did he recently get it or has he had it a long time and the car changed while he had it?

41 MPG? Maybe someone put cheap high rolling resistance tires on it?

He bought used. It has never cracked 46 MPG, no matter the speed, tire pressure, or weather conditions.

I'll have to check the tires next time I'm there to see if they are junk.

I checked the link. That is a huge amount of information ! (Thanks ! )

[Isaac Zachary]

Originally Posted by Cd

He bought used. It has never cracked 46 MPG, no matter the speed, tire pressure, or weather conditions.

I'll have to check the tires next time I'm there to see if they are junk.

I checked the link. That is a huge amount of information ! (Thanks ! )

I need to keep better track of my mileage. But there's been times this winter I didn't get much more than 20pmg. And there have been trips I've gotten over 50mph. There are a lot of variables that can affect the mileage in Prii and similar hybrids.

[rmay635703]

Originally Posted by Isaac Zachary

I need to keep better track of my mileage. But there's been times this winter I didn't get much more than 20pmg. And there have been trips I've gotten over 50mph. There are a lot of variables that can affect the mileage in Prii and similar hybrids.

The Gen II across the street gets 19mpg all winter (I should photograph his dash)

Nothing wrong with his Prius, just doesn’t drive far enough to get the engine warm

[TexasCotton]

Make sure that the front two Tires are a matching pair.
I have Bridgestone Ecopia 185/65/15R left and right front pair.

Shouty Kilmer aka Scotty Kilmer YouTube explains further reasoning