ColinBarber

I've never paid the extra insurance cover when it was a recall - the dealer gets money from Lexus to cover the cost (and additional money for extra petrol). Any dealer charging you has made a mistake, has a member of staff in need of training or is taking advantage of the situation.

5w30 is fine for that engine, in fact I'm not sure 0w20 was originally a recommended grade when the vehicle was new, although it was possibly retrospectively added later. If it is consuming 5w30 oil then it will certainly consume 0w20, probably more because it is thinner. If you haven't got a leak then ideally you want to known how the oil is being consumed. Valve guides, piston rings, excessive oil pressure etc.

When the 450h+ launched it had a £5k premium over the 350h - that is a lot if you aren't able to, or don't want to, plug in and charge to make use of the extra benefit it provides. Now Lexus has lowered the price to under £2k difference to help offset some of the penalties they will pay for not selling enough EVs, the 350h sales will no doubt suffer and I wouldn't be surprised if Lexus consolidate the range in the UK at some point. The 500h will probably go - I suspect Lexus need the different options in the US and other markets, but once they understand which one(s) sell in the UK the other will be removed.

Magnet is really all you can use to make sure it isn't full of filler. Underseal is a legitimate protection method but can equally be used to cover up issues.

Not ideal. You would be resetting the engine ECU so long term fuel trims need to be relearnt and you possibly have to go through a ISC reset procedure otherwise the hybrid system may not shut down the engine - affecting economy. Best to identify the issue and resolve.

Every time I believe. Definitely check for metal objects under the armrest - it will interfere (possibly in the ashtray too). It would be nice to resolve the issue rather than disabling the interior sensor every time.

The series II GS uses a microwave sensor not ultrasonics - you cannot tape over the sensor as it is buried within the centre console and the signal would just penetrate normal tape as it already goes through the console plastic.

Item 1 in the follow diagram (I've moved your question to a new post as it was off-topic in the IS forum).

When in Neutral the engine and transmission are disengaged. Therefore the petrol engine cannot drive the generator to charge the battery. This is a non-issue provided you use Park and not Neutral when stopped for more than a minute or two.

That might be the way to go if you can do without the car whilst it is being done.

I thought it was in the centre console on the GS series II but above. I'm not 100% sure but I believe to disable the interior sensors you should lock the car, wait 10 seconds and then lock again - 5 flashes will mean it has disabled the interior sensors.

I've used Total Car Check a couple of times for an 'HPI' check. £8.99 for a single use of their Gold service, much cheaper than some - although probably the same info as you would get for £4.95 from Autotrader - and both have a £30k guarantee.

Not too bad if that is to supply and fit with a decent warranty. It is unlikely to be a genuine Lexus part though.

I've not measured it but I suspect the latest models have a higher current draw than that. Smart entry means the vehicle is constantly transmitting a signal to find a key, plus bluetooth if the vehicle has digital key connectivity and Internet connectivity is always active to accept remote A/C commands etc.

Try using a reg number from the Lexus used car section of their website to see if that makes any difference. Some insurance companies do inflate premiums if you don't have the reg number.

Technically the hybrid system is still providing all electrical power for the vehicle when in N (the system is still in Ready mode). The issue is that when the hybrid/traction battery gets low the petrol engine cannot recharge and you therefore run the risk of fully discharging the battery which is very bad (although I'm sure the vehicle will just shut down before that happens).

It certainly gives up some power but it is the only model that directly compares. The 450h+ is a PHEV and the 500h has a higher performance turbo charged/auto transmission drivetrain for a different type of customer. Certainly Lexus designed the 350h has a replacement based on their press information "This 2.5-litre petrol drivetrain provides 247bhp/184kW and 0-62mph acceleration in 7.9 seconds, performance comparable with the current RX 450h, while at the same time producing lower emissions." A higher performance model is never going to be as efficient - your comparison on efficiency suggests you are thinking it is a replacement whereas it is aimed at a different type of buyer who's priority is not efficiency. It's no different than with the older 450h. Once the battery is depleted, full power cannot be achieved. But that rarely happens, the system will always store some energy in the battery when full power isn't being delivered so that it is available when it is called for. Whether you manually switch to hybrid mode, or it is forced because the battery charge is low, based on owners here you can expect to get around 50 mpg. If you charge up and operate in EV mode then you are getting up to 235 mpg in PHEV / mpg measurement. There is only one battery. If the battery depletes to a point where EV running isn't possible, but where some energy remains, it switches to a hybrid system and the same rules apply as with a traditional hybrid - you should get full system power provided you don't try and sustain full power indefinitely where the battery can no longer provide any assistance. In hybrid mode, the vehicle benefits from a larger battery compared to the older 450h - that makes it more efficient, along with the more efficient petrol engine. The traditional hybrids are compromised on battery size due to cost and space constraints. As the PHEV has a much larger battery, it can make use of that greater energy store even when just running as a normal hybrid.

The new 450h+ is definitely more efficient than the old 450h, even if you don't plug it in and charge it. V6 engines are all but gone - the emissions are too high to meet current targets.

As explained by the OP, the battery is new, and it isn't the first time it has had to be replaced.

The 500h isn't meant to be a gen4 450h replacement - that's the job of the gen5 350h and it is more efficient. The 500h is meant as a high performance version of the RX, way beyond the old 450h, and as a result uses more fuel.

Typically several unrelated codes appearing at once does suggest a 12v battery issue.

Hybrids don't typically do much better on a motorway run. Not sure why Lexus only publish the combined figure in Europe but in the US the two figures are essentially identical (although cannot be directly compared to Europe because of the different testing method and imperial vs US gallon size). The 450h+ has powerful electric motors so the petrol engine has to do less work (less revs) compared to the 350h for the same level of performance. Perhaps that's why you found it noisier.

DRLs were added to the facelift models in 2012.

That isn't a valid code. Possibly that's what your reader outputs when it cannot properly read a Lexus propriety code? Or the vehicle's computing isn't working correctly if the 12v supply is too low.

No, the 500h claimed mpg is around 35 mpg. The new 350h is the replacement of the old 450h, and that is more fuel efficient.