Volvo V90 plug-in hybrid long-term test: report 6

The car Volvo V90 Recharge T6 Inscription  Run by Jim Holder, editorial director

Why it’s here Can a large plug-in hybrid estate really deliver great fuel economy as well as carry-all practicality?

Needs to deliver A premium experience all round, from interior comfort and capability through to driving dynamics, while also hitting diesel-like efficiency

Mileage 4048 List price £58,300 Target Price £54,419 Price as tested £66,940 Test economy 48.2mpg

24 November 2021 – Words of warning on tyre pressures

It was half-term and we were packed up for a week away in Matlock, Derbyshire, which meant a car full of walking boots, heavy coats and multiple changes of clothes.

It also meant having to accept that the Volvo V90 plug-in hybrid wasn’t going to be near its efficient best, given that driveways in the part of town where we were staying – all steep hills and side-by-side housing – were at a premium, and ones with charging points even more so.

So I loaded up the car and family and unplugged the car at home at the last minute after one last top-up, jumped aboard and… discovered that I’d overlooked another fundamental of taking a long trip in a packed car. The tyre pressure warning light was on.

I’m not sure if electrically powered cars are more inclined to needing bespoke tyre pressures for heavier loads due to the inherent weight of their batteries, but I'd encountered this issue previously, on another electric car. 

So, after a gentle drive to check if it was safe to proceed, I headed to the nearest air supply at the local forecourt, noting irritably the fact that the big oil companies now charge for the convenience of using their pumps. 

I was glad I did, though, because I was quite shocked to discover that the pressure was 4psi below the minimum recommendation for even an unladen car. Given how sensitive cars can be to even 1psi of difference, I was surprised I hadn’t noticed even in the absence of the tyre pressure monitors offering a warning.

However, that realisation in turn led me to be a bit cautious in topping the air up; instead of going all out to the maximum limit – also recommended for the most efficient eco driving – I settled somewhere in between, reasoning it would likely do away with the need for a second trip to the pumps.

A shrewd move? I’m not so sure.

Not only has the tyre pressure warning light stayed on regardless of the circumstances in the subsequent weeks, whether it’s just me in the car or it's fully laden, but there's also been no noticeable difference in the car’s performance. 

I’ve checked for slow punctures, of which there is no sign, so the next step is a repeat trip to the garage to pump the tyres up to the maximum recommended 39psi – up from 31psi on my first check, and up again from 35psi now, so quite a significant jump. If that doesn’t persuade the sensor to reset, it’ll mean a trip to the dealer, I fear.

But perhaps of more consequence will be whether I notice any material differences in the ride, handling and fuel economy. The percentage shift is so big that I will worry both about my career choice and Volvo’s choice of settings if there really is nothing to report after putting all that extra air in.

My suspicion is that I will regret not going for maximum pressure all along, but I’m also keen to check I haven’t uncovered a niggle with the car’s onboard monitoring system. Why did it take a fully laden car for the warnings to show in the first place, and why, with the pressures well within the tolerance for the weight of the car, are they still showing now?

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