Is Prius Really Economical..?

[Blindrage]

Hello I became a Toyota Prius T-Spirit 2010 owner myself this month I bought a used Toyota on 44000 miles, apparently after loading the tank which has 45 liter capacity can get me 430 miles despite driving it in Eco mode most of the time... Is there something wrong with the Prius itself or is it me who is not driving it as its supposed to be driven ?

[FROSTYBALLS]

Moved to Hybrid/Toyota Prius club.

[johalareewi]

Welcome.

mpg depends on a few things.

Tyre pressures - make sure they are not under inflated.
Wrong type of tyres - should be low rolling resistance.
Wrong type of oil - should be 0w20 in a gen3 prius.
The weather - can't do much about that.
Driving style -

This question comes up time and time again.

Have a search through the forum.

[AGL]

The range / size of tank is a bit mystifying.

If I brim mine, when on the last section of the tank, I can get about 37 litres in. It would seem the fuel gauge shows 'empty' when there's the best part of a couple of gallons in there!

I've not pushed it to zero, or past, but it's a bit of a pain having to fill up every 5 days when, in actual fact, it could quite safely be every 7.

So, rest assured, you're not getting 430 miles for your 45 litres. It's probably 430 mile for 36 litres, so about 53mpg.

[theoilburner]

Yeah, I filled up our Prius on Saturday. Range was showing about 20 miles and the fuel gauge was nearly at the bottom.

After squeezing in every drop I could, I only managed to get in 39 litres. This is normal for a Toyota, the fuel gauge and range are always very pessimistic.

I remember driving about 70 miles on my old Avensis with the range showing zero and the gauge on rock bottom. It still had about 3 litres in when I finally filled it up.

In other words, forget "miles per tank", do a proper brim-to-brim measurement. Economy mpg = (Miles driven / fuel in litres) * 4.546

The Prius should give you somewhere between 45 to 65 mpg depending on how you drive it, use of air-con/heating, tyre pressures etc etc.

That will mean around 350 to 500 miles from full to the fuel light coming on.

[cabcurtains]

I'm glad all the Prius's are like this, i thought ours was being odd! The range displayed 0 miles and it only took 32 litres!

[Chris Dance]

Agree with johalareewi. Tyre pressures are very important and also the type of oil used it must be ow20. At this time of year you should get 60+ MPG.

[Duffryn]

OP - Have you tried Fuelly for more accurate mpg calculations?

[Blindrage]

What is supposed to be the tire pressure ? And about one more thing I haven't received a log book from toyota is everything supposed to be registered on my Computer I've logged into General and then to Vehicle and for some reason all the data was deleted

[Chris Dance]

Tyre Pressures are on the drvers side door post.

[kithmo]

What is supposed to be the tire pressure ? And about one more thing I haven't received a log book from toyota is everything supposed to be registered on my Computer I've logged into General and then to Vehicle and for some reason all the data was deleted

The vehicle data is entered by you, it is like a personal record that you keep to remind you of what wants doing and when. For example if you have it serviced then enter the next service due as 10000 miles and 1 year later, it will then count down and the item will turn orange when it's due. The previous owner either didn't use the feature or they deleted everything. Tyre pressures are supposed to be around 30psi front and 32psi rear IIRC. I used to run them higher for economy about 33psi front and 35psi rear on my Gen3.

[timberwolf]

What is supposed to be the tire pressure ? And about one more thing I haven't received a log book from toyota is everything supposed to be registered on my Computer I've logged into General and then to Vehicle and for some reason all the data was deleted

The vehicle data is entered by you, it is like a personal record that you keep to remind you of what wants doing and when. For example if you have it serviced then enter the next service due as 10000 miles and 1 year later, it will then count down and the item will turn orange when it's due. The previous owner either didn't use the feature or they deleted everything. Tyre pressures are supposed to be around 30psi front and 32psi rear IIRC. I used to run them higher for economy about 33psi front and 35psi rear on my Gen3.

Erm, that is the wrong way around, you want the higher tyre pressure at the front of the car, because of the weight of the engine and when braking the force is thrown forward and downward onto the tyres (at least that is my layman's view - well respected physicists are probably turning in their graves as write this! ).

[kithmo]

What is supposed to be the tire pressure ? And about one more thing I haven't received a log book from toyota is everything supposed to be registered on my Computer I've logged into General and then to Vehicle and for some reason all the data was deleted

The vehicle data is entered by you, it is like a personal record that you keep to remind you of what wants doing and when. For example if you have it serviced then enter the next service due as 10000 miles and 1 year later, it will then count down and the item will turn orange when it's due. The previous owner either didn't use the feature or they deleted everything. Tyre pressures are supposed to be around 30psi front and 32psi rear IIRC. I used to run them higher for economy about 33psi front and 35psi rear on my Gen3.

Erm, that is the wrong way around, you want the higher tyre pressure at the front of the car, because of the weight of the engine and when braking the force is thrown forward and downward onto the tyres (at least that is my layman's view - well respected physicists are probably turning in their graves as write this! ).

You're right, I should have said 33 front, 32 rear, I used to put 3 or 4 psi extra in. Interestingly my Prius plus is 32psi all round (i set to 35).

[jonesbach]

....................one more thing I haven't received a log book from toyota is everything supposed to be registered on my Computer I've logged into General and then to Vehicle and for some reason all the data was deleted

I have an Auris and this may be different for the Prius. I did not receive a log book as such, but was provided with a 'Service & Warranty' booklet that has spaces to record your service history.

With regard to the online info.(MyToyota Dashboard) I have had occasional problems where this is not properly displayed. On checking today it is showing all my interaction with the dealer. NOTE: PUT IN BY THEM, NOT ME.

Did the dealer provide you with the username/password. For privacy reasons the system should not allow anyone to create a second account and be able to view the content.

[timberwolf]

Yes, same tyre pressures all around is different.

[johalareewi]

You're right, I should have said 33 front, 32 rear

Is that for the 17inch low profile tyres?

The 15inch tyres on a gen3 are 36psi (or 38/36).

[Sagitar]

The original question was "Is the Prius really economical"? Most of the subsequent discussion has been about mileage, but that is generally a minor part of the cost of running a vehicle, though it's perfectly understandable why it gets so much attention.

I bought my Prius new and it is now four years old. I am a relatively low-mileage user, so the fixed costs are more important to me than the variable costs. In the whole of the time that I have had the car, the variable costs (which includes petrol of course) have been 15p a mile. The fixed cost however have been 109p a mile.

My previous car was a Lexus IS250, also bought new and kept for three years. The variable cost was 22p a mile and the fixed cost 110p a mile. You would need to apply four years of inflation (petrol up about 40%) to compare the figures so (no surprise here!) the Prius is significantly more economical than was the Lexus.

The possible variability of petrol costs is admirably demonstrated on Fuelly and the oft-repeated advice to have a look there is still valid.

Tyre pressures undoubtedly make a difference. I run mine at significantly higher pressures than the handbook recommendation, but it is not specifically for reasons of petrol economy. I watch the pattern of wear on the tyres and adjust the pressures until I get even wear across the width of the tyres. The last service on the car (at the beginning of September) showed that the worst tread depth variation on any of the tyres is less than a millimetre.

I am delighted to have good petrol economy, but I don't use any "extreme" driving techniques to achieve it. I don't fiddle with the driving modes - can't remember when I last engaged ECO or Power mode. Most of my journeys are short and local and I have concluded that that is the main reason why my economy is not as good as some others.

The whole issue is quite complex and there are no "silver bullets" in my experience.

[Peter Sale]

I bought a Tyrepal tyre pressure monitor a few weeks ago to give me peace of mind rather than crawling round checking the pressures every week.

For those interested, the tyre pressures increase all round by 3 psi when reasonaly warm - running at about 65 mph on a cloudy day. Running at about 70 mph on a sunny day took the front tyres on my Auris up 5 psi from 33 to 38 psi.

Peter

[kithmo]

You're right, I should have said 33 front, 32 rear

Is that for the 17inch low profile tyres?

The 15inch tyres on a gen3 are 36psi (or 38/36).

Yes, it was aT-Spirit.

[Joseph D]

Tyre pressures undoubtedly make a difference. I run mine at significantly higher pressures than the handbook recommendation, but it is not specifically for reasons of petrol economy. I watch the pattern of wear on the tyres and adjust the pressures until I get even wear across the width of the tyres. The last service on the car (at the beginning of September) showed that the worst tread depth variation on any of the tyres is less than a millimetre.

I do the same and for the same reasons. I noticed that when running the tyre pressures as per the handbook (35/33) the tyres were wearing more on both edges (indicating under inflation), so I run my 195/55/R16 tyres at 39/37 which gives me even wear.

[Cyker]

That's weird; I wonder how common this is?

I had noticed the same issues on my Yaris' front tyres and, when experimenting with over-inflation for the mpgeeez, also found it massively reduced the problem!

I was wondering if maybe it needed specific tyres, but so far I've observed the same issue on the original Bridgestone and Firestone tyres I bought the car with, and the Continentals that replaced them...

Does steering/suspension geometry need adjusting from time to time...?

[Sagitar]

It's a common issue. The manufacturer needs to establish an average inflation pressure that works in a wide range of circumstances. The establishment of this pressure cannot be an exact science because the variables involved cover such a wide range. There are also compromises about which different drivers will make different decisions. For example, some drivers will prefer a softer ride while others will put up with a harder ride for improved tyre life etc.

A driver who is prepared to check pressures regularly and measure tread wear accurately can exercise some control over the consistency of wear across the width of the tyre. This is essentially about using pressure to vary the profile across the tyre from concave to convex and vice versa so that wear is evened out. Of course, if you persistently "door-handle" at high speed around tight corners you will wear the edge of the tyres no matter what inflation pressure you choose,

[Birty]

Whats fuelly. Cant find on web!

[Joseph D]

Whats fuelly. Cant find on web!

Fuelly is a site hosted in the USA and used worldwide, including here in the UK, that helps you keep track of your fuel mileage over time, using data you provide. Any and all information added to the site is public, so be mindful of how much information you want to share online. Your fuel data is public and shared with other drivers and visitors to the site. The website is www.fuelly.com. All you need to do is create an account, add a car and start recording your fuel ups.

HTH

[Birty]

Thanks, will take a peek!