Thackeray

For short journeys in winter, 38 mpg doesn't look bad. If you switch to the energy consumption screen (press something like Menu/ Car / Trip Information you'll see something like this: If you watch this screen when you start from cold in the snow with the heater on, the heated seats, heated rear screen, wipers plus maybe lights and some other things, you'll see that you're getting about 20 mpg in each of the first five minutes while the car warms up. Each minute of the journey is represented by one bar of the graph. If you end the journey before the car has fully warmed up, you'll get low mpg. But after, say, 10 minutes when the engine has reached its normal operating temperature mpg will improve, even in winter. And it warms up quickly in the summer and mpg improves even for short journeys, so over the year it all balances it out.

The good news is the IS300h has really easy to use isofix brackets, neatly hidden behind a little plastic flap. By contrast, some cars, like the Toyota Auris, have the brackets hidden in the recess at the angle beween the base and back cushions of the seat. Extremely difficult to slot in the seat-base isofix connectors. And just in case you want to start saving up now, this is a link to one of the Britax seats that revolve 360 degrees so that the child can face backwards up to about the age of 4. I'm sure there will be other brands or options by the time you need it but this is the sort of seat where the child can face backwards for longer.

It might be the USB formatting, as Paul says. Just to check, have you tried pressing the Media button on the radio repeatedly to cycle through the available inputs? I think the USB slots should be one of the options if you do this. Apologies if you've already tried this and it doesn't work.

And once the engine doesn't need to run for other operational reasons (such as charging the hybrid battery, reaching operating temperature) you can start and stop the engine just by turning the climate control on and off.

This is the best advice. For a new-born, get an isofix base that lets you, ideally, unclip the babyseat from the pushchair and then in the car slot it into the clips on the isofix base. I spent a couple of years using a baby seat without an isofix base and the problem was that when you put the baby carrier on the car seat, you then have to strap the seatbelt over and round the seat and baby, who is already strapped into the seat. At the destination, you then have to unclip and rewind the seat belt. Much easier just to press a button and lift the seat and baby straight out. Having said that, if you don't want to buy the base, from the safety point of view I always assumed that although the seatbelt doesn't hold the baby seat rigidly, all the seatbelts would lock in a crash, securing the baby seat as effectively as a it would secure a seated passenger. I've never heard of seatbelts that can lock round a baby seat though looking on the internet, there seem to be some examples on older cars. When you get to the next stage, if you can afford it, it's safest to get a child seat that allows the child to face backwards up to the age of four. The Britax one swivels and can face backwards or forwards. The problem with small children facing forwards is that in a crash their head is thrown forward and it represents a lot of the child's total weight, proportional to its body. This can cause damage to the neck and spine, I think. Facing backwards, this doesn't happen, so it's much safer.

So where is RoyoftheRovers when you need him with his manual? I'll just have to find my own manual! Here's what it says on page 312 about winter driving tips: Having said that, you're absolutely right. The parking pawl shouldn't be used to hold the weight of the car. I would never leave the car resting on the parking pawl - I only leave it just in Park when the ground is completely flat. If I can feel the car move and the transmission lock by hitting the parking pawl I would always apply the parking brake and I'd probably put the car back in Drive first for a moment to release the parking pawl before applying the parking brake. It's just that where I leave the car overnight I know I can just leave it in Park without any likelihood of the car moving. So you're right that the best advice is probably always to engage the parking brake when parking unless you're confident about what's happening in the transmission. Even the manual's advice might not be ideal. Herbie, you'd better get the handbook correspondent to write and tell them.

I rarely use the foot operated parking brake. When I leave the car at night I just leave the gear selector in Park and like a conventional automatic that locks the transmission. But this isn't robust enough to hold the car on a hill so I use the parking brake if I'm parking on a hill. If you're doing a hill start you don't need to operate the parking brake. When you take your foot off the footbrake the car is held automatically by the brakes for around 3-4 seconds to give you time to shift your foot to the accelerator. But if you don't press the accelerator the car will start to roll backwards after these few seconds. And at traffic lights you just keep your foot on the footbrake until the lights change.

You may find it strange at first if your driving instincts expect to be changing gear. Part of what people like about an involved driving experience is the rev of the engine and the jolt as you change gear. You don't get that with an automatic. Instead, as you know, you pretty much keep your accelerator foot in one position rather than the dance between the accelerator and clutch in a manual car. The so-called eCVT in the IS300h is smoother than a conventional automatic because whereas you can still feel the gear changes in conventional automatics, in the Lexus hybrid there are no gear changes. The transmission is a permanently meshed planetary gearset. So it's completely smooth. Some people find that disconcerting at first. Instead, when you put your foot down the engine immediately races, rather like a plane applying full throttle, and then eases off as you reach the required speed. That can be disconcerting too and a lot of motoring journalists have been critical of this. And the car is limited to 125 mph to protect the electric motors which might be damaged if they turned too fast, so journalists aren't keen on that either. But most journalists don't live with the car. Most on this forum who use the car daily seem to like it a lot. Personally, I think the transmission is great. Very quiet, hardly any moving parts to go wrong. Completely smooth. Rather like driving an electric car except for the racing engine when you use full throttle. Would I get another one? Absolutely. I haven't owned manuals for 20 years or more and as an automatic this is the best I've had.

Welcome to the forum. Not everyone is used to driving an automatic and make comparisons with the manual cars they're familiar with. Was your Volvo V40 D4 an automatic? Are you used to driving automatics?

You could try letting the engine warm up for a minute before setting off. You can check power generation has started on the energy monitor screen. Then set off exactly as you normally would and see if you still feel the jolt. Of course, you might still feel the jolt while you're stationary - it's certainly possible to hear the generator increase power when the engine warm-up stage is right.

I'm not sure that's right. It's the petrol engine which isn't sufficient to power the car until it's gone through the first warm up stages. During this time, as I understand it, it's mostly the battery that gets the car moving. If that's wrong I hope someone will correct it.

If it only happens from cold, could it be power generation kicking in and applying a load to the transmission after the engine has warmed up, going through the various stages. Here's a Prius forum where the various engine warm-up stages are described. Scroll down to the post by Grumpy Cabbie about half way down that lists the engine stages. You can watch the car's energy monitor screen to see when power generation begins - it's usually after about a minute. Or you could use the Hybrid Assistant app if you have an Android phone which shows the power generation begin in more detail and also specifies which engine stage the engine is running in. If power generation begins when you feel the jolt that may be the reason. Having said that, I wouldn't have thought it would be very noticeable, so maybe there is a problem of some sort.

The point of the battery is to store the electricity regenerated when braking. If the battery is full, there's no room for the regenerated electricity and it has to be thrown away as heat. So the computer aims to keep it at around 50% charge (or it does on the IS300h anyway). This is a reasonable compromise between leaving plenty of storage space for regenerated electricity, but enough power for an extra burst of acceleration. In practice, it's charging and discharging second by second. If you press the accelerator some power from the battery will often be added to the power of the engine. But as soon as you lift your foot off the accelerator the motor operates as a generator and produces some electricity to store in the battery. If you put the car at a fixed speed on cruise control you can see this happening second by second on the screen graphic. The computer also keeps the battery in a range of 40-80% as this prolongs its life. So one bar on the dashboard meter is around 40% charge and eight bars on the meter is around 80%. So to answer your question, the engine will be running most of the time, assisted by the electric motors from time to time. Though on a long flat stretch at 30 mph it might switch to electric only for a while, but not more than a mile or so.

One possibility for the fuel consumption is that it's winter. Consumption always rises when it's cold because the engine runs to keep the cabin warm whereas in summer it would stop. There are also a lot more demands on power like heated seats, wipers, lights etc. The effect is worse if you do a lot of short trips of 10 minutes or less. If the engine never reaches normal operating temperature fuel consumption will suffer. Your long term mpg is 42 mpg (US gallons). The car computer usually overstates the number by 8-10%, so that's a real 38 US mpg. (For non-US readers that's around 47 UK mpg or 6 litres per 100 km.) This is pretty good. The average for the IS300h on the fuel consumption website spritmonitor.de is around 35 US mpg or 44 UK mpg or 6.47 l/100km. If your inverter overheated, fuel consumption would suffer, so the drop in fuel consumption for that tank is not surprising. But my guess is that the computer would cut back use of the inverter if it was overheating to avoid damage. There's also a limit on charge and discharge of the battery which is constantly adjusted to avoid damage so I could be wrong but it seems unlikely that the battery would have been affected. Instead, the use of the battery would have been reduced if the inverter wasn't operating to full capacity. If the inverter had stopped working altogether, I don't think the car would be able to move. After the problem was fixed consumption has been 31 mpg (let's say a real 28 US mpg, 35 UK mpg, 8.2 l/100km). That's disappointing but not extraordinary for winter driving. And you can't compare a one-off 31 mpg in winter with a long-term average of 42 which has been built up over many months including the summer when consumption is best. If you have figures for previous winters you could compare and see if this is worse.

Looks like this was your first post so welcome to the forum! You raise some interesting questions and it would be good if you could clarify some points. What were the coolants that were changed? Does your bill specify what was done? You mention an overheat light, as well as an error message. Do you remember which light it was and what the wording of the error message was? And just for background was it mid 30s outside in fahrenheit (you needed heating) or centigrade (you needed cooling). If it's fahrenheit I'm guessing you're in the US and maybe your mpg figures are based on US gallons. I have read that bubbles in the inverter water cooling system on the Prius can cause overheating but I'm not sure if it's the same on the IS300h. Some more expert contributors will no doubt provide some more info. As for the coolant changes, in the UK as far as I remember the only extra task at 60,000 miles is spark plug replacement.

Just to clarify the situation, are you pressing the defrost button and it's taking 15 minutes from a cold startup? And as Nemesis says, is it really frost on the interior, or just frozen mist? And lastly, is the screen ultra clean to begin with and the air conditioning is on and working correctly?

That's exactly the same behaviour as my IS300h. During the coronavirus lockdown last year I needed to keep the 12volt battery charged and as recommended by Lexus I put the car in Ready for an hour a week. Having nothing better to do, I logged the hybrid battery state of charge and when the engine started and stopped, (as well as the 12 volt battery charge). I don't have Techstream but I was also using the Hybrid Assistant app which shows a lot of useful data including the percentage charge of the hybrid battery. What I found was that the hybrid battery charge would run down to 40% (equivalent to two bars on the dashboard meter) and then the engine would start. It would keep running until the hybrid battery reached 50% charge, which was displayed as three bars, and then the engine would stop. The state of charge would then gradually go down again (I had the radio on too but I doubt it uses a lot of charge compared with the air conditioning which was also on.) After 10 minutes it was down to 40% again (two bars) and the engine would start again. And so on. This was at outdoor temperatures when little or no heating was needed. In winter weather the engine will keep running a bit longer to keep the cabin warm and the bars on the battery gauge will go higher than three. The instinct of most people when they start using this hybrid system is to want the battery to be full, as you would with the petrol tank. But the point of the battery is to store spare electricity generated from braking. If the battery is already full the car has to throw away the energy as heat. So a good compromise level for the battery is around 50% - that leaves plenty of capacity to store regenerated energy but at the same time has a good store of energy to add to a sudden burst of acceleration. Incidentally, the bars don't represent the battery's actual capacity. The computer will aim to prevent the battery going below 40% by starting the engine, or above 80% by using the electric motor to spin the engine without using petrol, which you might notice happening after going down a long hill and getting up to eight bars on the meter. Keeping the battery within this 40-80% range prolongs its working life.

Here's a video about turning off the screen. In the comments after the video, some people are asking how you turn it back on. The answer in this case seems to be press and hold the Menu button (or the Home button, though my car doesn't have a Home button). I'm sure you've tried everything already but if you haven't tried pressing and holding Menu, maybe it's worth a try.

There is a setting to turn off the screen. That being the case, it might be a software issue.

My thinking on nitrogen is that it's probably not worth paying for. When you get new tyres they will be filled with 78% nitrogen, as Mike points out. Most of the rest is oxygen and my understanding is that because oxygen molecules are smaller than nitrogen, they can seep through the rubber whereas the nitrogen doesn't, or not so much. If all the oxygen seeps out and you have to top up the tyres, the lost 22% volume of gas (which was 100% oxygen) is replaced with air (which is 22% oxygen). So after one top-up the oxygen is now about 5% of the total volume of gas (22% of 22%) and nitrogen about 95%. After a second topup the 5% oxygen becomes 1% oxygen and 99% nitrogen. So I'm not sure there's much benefit in paying for nitrogen. It's different for formula one, of course, where tyre pressures need to be exactly right all the time.

You may already have looked at this but there's a lot of useful background information on the Weber Auto youtube channel about Prius batteries and electrical systems. Here's one of the videos but there are others that could be useful.

I turned mine off four or five months ago in the hope that it might reduce battery drain. I can't remember the exact menu steps but the manual says it's Menu/Setup/Vehicle. However, I'm not sure that it's had much of an impact. The battery still needs to be charged every week. I haven't tried turning it on again to compare and I don't know where I could measure the battery drain with a multimeter. If it's easy to do, maybe someone can tell me how to do this. But the thing is, I suspect that as soon as you open the car all the electronics wake up so it would be hard to measure the battery drain in its sleeping state. When I left a Carista OBD adapter plugged in for a week that had a much bigger impact and pushed the voltage down to around 11.5 volts.

Now that it's getting dark I've tried the dimmer control on my car. There are two settings for the dimmer - one when it's daylight and one when it's dark and the headlights are on. The manual says there are two settings depending on whether the tail lights are on or not but I'm not sure that's correct as I can't get to the second setting until the car senses it's dark outside. When it's dark and I turn on the lights, the instrument panel lights dim to the level that's been preset. I can control this up and down and although the lights on the aircon and the clock go quite dim they don't go out completely. I know this doesn't help solve your problem but at least this is what I imagine is supposed to happen. It'll be interesting to hear if you find out what the problem is.

Yes, you've reminded me that the most frequent fault logged by the computer support team at a firm where I once worked was " N.P.I. ". (Not Plugged In.)

If a mechanic has checked it, this may be a silly suggestion but is the panel light dimmer control turned right down?