Intentional News

20260912 Replace the Lexus CT fuel source and bidirectional options

12 min read

Decision — Replacing the 10-year-old Lexus CT: fuel source and the bidirectional question

Short answer (Alf’s read)

  1. Fuel, if you replace: electricity, now. Not hydrogen, not another hybrid, and solid-state is not a reason to wait.
  2. But at 4,000 miles/yr, replacement does not pay for itself. The fuel saving is £470–£590/yr; depreciation on anything new is £2,000–£3,500/yr, and tax rises by ~£300/yr once pay-per-mile starts in April 2028. The money answer is: run the CT on.
  3. Bidirectional: buy the capability in the car, not the charger. A handful of £21–29k cars can now power the house; the wallbox that unlocks it still costs £3,500–£7,750 and pays back over 8–20 years at today’s prices. Put a normal £1,000 smart charger in now; add the bidirectional unit when prices fall or when solar + a home battery goes in.

The four inputs that decide this

InputStatus
Annual mileage~4,000 miles (very low — this is the decisive one)
Tax position nowVED band A, £20/yr (94 g/km, pre-2017 CO2 bands); every replacement pays £200+
Off-street parking for a home chargerNot yet given — a driveway is the difference between 8p/mile and 26p/mile running costs
Longest regular journey + budget / lease vs buyNot yet given

The arithmetic at 4,000 miles a year

Assumptions: petrol 167.17p/litre (RAC, Sept 2026 — a four-year high, up 5p in a week on the Iran war; diesel 188.63p). CT real-world economy 45–55 mpg on a 10-year-old 1.8 hybrid (the 68.9 mpg brochure figure is not real). Home charging 6.99–26.11p/kWh; EV efficiency 3.5–4.2 mi/kWh.

  • CT fuel: 331–404 litres/yr → £553–£676/yr
  • Equivalent BEV, home charging: 950–1,145 kWh/yr → £67–£92/yr on an EV tariff (Octopus Intelligent Go 8p, EDF GoElectric 6.99p); £250–£298/yr on the standard variable tariff with no smart deal
  • Fuel saving: £470–£590/yr — the strongest number in the EV case
  • VED: CT £20 → any replacement £200 standard rate (+£440/yr if list price is over £40k petrol/hybrid, £50k EV) = +£180/yr now
  • From April 2028, pay-per-mile (eVED) starts: 3p/mile for EVs (£120/yr at 4,000 miles), 1.5p/mile for PHEVs — total EV tax £320/yr, i.e. +£300/yr vs the CT. the owner’s “£250 at least” estimate is essentially right, and he got there before the arithmetic did.
  • Servicing/tyres/insurance: EVs save ~£100–£250/yr on fluids, filters and brake wear but eat tyres faster; EV insurance often runs £50–£200/yr higher — worth a quote before deciding
  • Net running saving: ~£290–£410/yr today, ~£170–£290/yr from 2028
  • Against that: depreciation. Anything new loses roughly £2,000–£3,500/yr in its early years — 5–10× the entire running-cost saving. At 4,000 miles/yr the car is stationary most of the time; you are paying depreciation on an asset you barely use

Also true and worth saying: keeping a reliable car running is normally the lowest-carbon choice too. At this mileage the CT is a good car doing very little harm.

Update — 13 September 2026: does the oil spike change this?

Petrol has moved again since this note was written. Brent closed Friday 11 Sep at $104.61 (+8.7% on the week, the biggest weekly gain since July), and over the weekend of 12–13 Sep a projectile struck a vessel in the Strait of Hormuz — unprinted risk, meaning there is no market price for it until Monday. So it is fair to ask whether a higher oil price changes the answer above.

It does not — and here is the number that shows why.

  • At 4,000 miles a year the CT burns only 331–404 litres. Every extra 10p on a litre costs £33–£40 a year.
  • A 50% jump in petrol (167.17p → ~250p) costs £273–£334 more a year. Against £2,000–£3,500 a year of depreciation on anything newer, that closes a tenth of the gap.
  • Petrol would have to reach roughly £6.12–£10.20 a litre — 3.7× to 6.1× today’s price — before the fuel saving alone covered the depreciation.

The conclusion is unchanged, and it is now tested rather than assumed. At this mileage fuel cannot carry the decision, because the car is stationary for most of the year.

Three things the shock does touch:

  • Diesel is the sharper end (188.63p/l, up 5p in a week; US retail diesel set a record above $6/gallon). It still does not close a £2,000+ gap at 4,000 miles.
  • It strengthens the battery-as-asset case, not the fuel case — see the bidirectional section below. If solar and a home battery go in, the same battery does two jobs and the V2G argument stops depending on mileage. That was always the one argument that survived this arithmetic.
  • It raises the running cost of the alternative you keep — which is an argument for servicing and tyres done properly, not for replacing the car.

So what actually justifies replacing it?

  • CT develops real repair bills — my trigger: ~£1,000 in one hit, or ~£1,500/yr ongoing
  • MOT failure / structural corrosion / parts availability
  • A new household need (second car, family logistics, a young driver)
  • Wanting the car to double as home storage (the battery-as-asset case — see below; this is the one argument that doesn’t depend on mileage)
  • Adding solar + a home battery — it changes the whole calculation
  • Values, comfort, safety tech, or simply wanting a new car — legitimate, just not a saving. Best to be honest that this is the real reason if it is

Not a trigger today: ULEZ/CAZ. The CT200h is Euro 5 petrol, so it is compliant with London’s ULEZ and the current clean-air zones.

If replacing: what fuel?

  1. BEV charged at home — the default. Cheapest to run by a wide margin, no servicing complexity, and home charging is now ordinary (see the Everything Electric road-trip item in the linked note).
  2. BEV with bidirectional capability built in — the option worth paying a small premium for, because the car becomes home storage. Details below.
  3. PHEV — only if you will genuinely plug in daily. Otherwise it is a heavier hybrid carrying dead weight, and it gets the worst of both worlds on tax after 2028 (1.5p/mile plus fuel).
  4. Another conventional hybrid — the weakest option: same fossil fuel, more complexity than either.
  5. Hydrogen — not in play for a UK family car; no refuelling network.
  6. Waiting for solid-state — the wrong reason to wait. First cars are expected to be low-volume Lexus flagships in 2027–28, affordable ones nearer 2030.

The bidirectional question: where is the choice?

The three things people conflate:

  • V2L (vehicle-to-load) — a socket on the car (3.3–3.6 kW) to run a kettle or a campsite. Most “bidirectional” spec sheets actually mean this.
  • V2H (vehicle-to-home) — the car runs your house. Needs a bidirectional onboard charger in the car and a bidirectional wallbox wired to the consumer unit. A normal 7 kW charger cannot do this and cannot be upgraded to it.
  • V2G (vehicle-to-grid) — the car exports to the grid for payment. Needs the same hardware, plus G99 approval from the network operator and a V2G tariff.

Both halves must support it. That is why the answer to “where is the choice?” is: in the car, first.

Cars on sale in the UK with real bidirectional capability (verified against manufacturer and charger-maker documentation, 2026):

  • Renault 5 E-Tech — from £22,995 OTR (£21,495 after the £1,500 Electric Car Grant; 52 kWh trims can attract £3,750). V2L standard on all trims, and V2H via Renault’s own Mobilize PowerBox Verso AC bidirectional wallbox — the cleanest factory design on sale. V2G service has been live in France since 2024; UK deployment during 2026. Cheapest realistic route to a car that can power the house.
  • Kia EV2 — from £24,245, 61 kWh long-range, up to 281 miles; V2G/V2L reported standard on all trims. Deliveries from later in 2026, with a £3,750 reservation saving pending grant confirmation. Verify at launch that the UK trim ships with V2G enabled — this is the classic gap between press release and spec sheet.
  • Nissan Leaf (3rd gen, 2026) — from £28,849, CCS (dropping CHAdeMO), onboard AC bidirectional charging, V2G enabled with Nissan’s own home charger, built in Sunderland and launched in the UK first. The most mature V2G path in the country, and Nissan explicitly warrants V2H use.
  • Kia EV9 / Hyundai Ioniq 5 / Kia EV6 — E-GMP cars with CCS V2X; the EV9 (99.8 kWh) is the one commonly cited as V2G-capable today with a Wallbox Quasar 2. Ioniq 5 rollouts are staged by model year.
  • VW ID range, Polestar 3/4, Cupra Born, MG4/MG5 — V2H announced or capable on some variants; check trim by trim.
  • BYD Dolphin — V2G only in the Octopus Power Pack bundle variant.
  • Tesla — none. No V2G/V2H on any current model. If bidirectional matters, Tesla is out, full stop.
  • Watch out — V2L only, not a home battery: MG4, Hyundai Ioniq 6, Kia EV6 (V2L), Kia Niro EV, BYD Atto 3, Volvo EX30.

Chargers (a bidirectional unit is mandatory):

  • Wallbox Quasar 2 — ~£6,100 hardware, ~£7,750 fully installed (CCS). The reference product.
  • Indra V2H — £3,500–£4,500 fitted, but CHAdeMO-heavy (Leaf 2nd gen) — a shrinking ecosystem, though it covers some CCS cars too.
  • SigEnergy — hardware £1,200–£2,500 plus installation from £800, so roughly £2,000–£3,300; firmware-upgradable to V2G and integrates with their home battery. This is the price floor moving, and the one to watch.
  • Zaptec Pro — via the Octopus Power Pack bundle (BYD Dolphin).
  • Comparison: an ordinary 7 kW smart charger is £800–£1,200 installed. So bidirectional carries a £2,500–£5,000 premium today.

What it earns (be sceptical here):

  • Octopus Power Pack is the only live UK V2G tariff: marketed as “up to £620/yr”, delivered as free charging plus export rather than cash. Conditions: plugged in ≥12 hours on ≥20 nights a month, household use under 210 kWh/month (~625 miles). At 4,000 miles/yr, the owner fits inside that comfortably — which is genuinely in his favour.
  • Realistic net benefit over a good smart tariff: ~£160–£620/yr. V2H peak-shifting is worth ~£400–£800/yr only for a high-consumption, electrically heated home on a time-of-use tariff.
  • Payback: 8 years at the cheap end (SigEnergy-class, £3,300, £400/yr) to 20+ years at the Quasar 2’s installed price. The Quasar 2’s 5-year warranty expires before payback in the average case.
  • Caveat that matters: Octopus cut its off-peak rate in April 2026, which narrowed the advantage Power Pack holds over a plain smart tariff. Re-check the current comparison before buying anything.
  • Battery wear: real but modest — roughly an extra 365 partial cycles/yr against ~150 for driving. LFP packs (BYD Blade, CATL) tolerate it well; NMC packs less so. Nissan warranting V2H on the Leaf is a meaningful signal.

My recommendation (Alf)

Ranked for this household, and revised from my earlier “BEV now” answer because 4,000 miles changes the arithmetic:

  1. Keep the CT running. It is £20/yr in tax, ~£550–£675/yr in fuel, from the UK’s most reliable brand, and ULEZ-compliant. Revisit when repair bills cross the trigger above, or when one of the other triggers lands. This is the money answer and I would not talk him out of it.
  2. If replacing anyway: a small BEV bought cheaply and kept 8+ years — Renault 5 E-Tech or Kia EV2 class, £21–25k after grant, £67–£92/yr to “fuel”. Depreciation is then the only real cost, and holding the car long is how you beat it.
  3. For bidirectional: buy the capability, not the charger. Prefer a car that has it onboard (R5, EV2, Leaf 3); fit an ordinary smart charger now (~£1,000); add the bidirectional wallbox when SigEnergy-class units land under ~£1,500, or when solar + home battery goes in. That is the point where payback becomes credible — and the car will still do it, because the capability lives in the car.
  4. Do not wait for solid-state. It arrives first in Lexus flagships at flagship prices.
  5. Do not buy a PHEV unless daily plug-in is realistic.

Watch list — dates to re-check

  • April 2028 — pay-per-mile eVED begins (EV 3p/mile, PHEV 1.5p/mile); EV tax becomes ~£320/yr
  • Late 2026 → 2027 — Kia EV2 deliveries; Renault Mobilize V2G UK launch; Nissan Leaf 3 V2G wallbox and tariff pricing; Nissan Ariya bidirectional update
  • Ongoing — Octopus Power Pack terms vs plain smart tariffs; bidirectional wallbox prices (tipping point for us: £1,500)
  • To 31 March 2030 — Electric Car Grant (£1,500 / £3,750 bands)
  • 2030 — ban on new petrol/hybrid car sales (with the lobbying to weaken it still live)

Open questions (two inputs still missing)

  1. Off-street parking / driveway for a home charger — yes or no? (This is the single biggest swing factor.)
  2. Longest regular journey, and any towing/holiday pattern?
  3. Budget, and lease vs buy?
  4. Any plan for solar, a home battery or a heat pump in the next few years?
  5. Has anyone got an insurance quote for a small EV, to keep prices honest?

📍 Everything Electric Greater London (Allianz Stadium, Twickenham, 11–12 September 2026) — what to ask on the stands

The show behind the video in the trigger note. Stands worth the time, and the three questions that matter:

  • Nissan — Leaf 3 V2G: ask what the wallbox costs installed and when the Power Pack equivalent is live
  • Renault — R5 + Mobilize PowerBox Verso: ask whether UK V2H is live or still “during 2026”
  • Kia — EV2: ask whether V2G is enabled on UK trims, or V2L only
  • Charger stands (Indra, Wallbox, SigEnergy, Zaptec) — ask installed price including G99 approval, and whether the unit upgrades to V2G by firmware
  • Octopus Energy — ask what Power Pack pays today versus Intelligent Go, given the April 2026 off-peak cut
  • The three questions for every car: Does this trim have bidirectional enabled in the UK, or just V2L? What is the installed price of the wallbox? What is the list price (the £50k EV threshold decides the £440 supplement)?
  • The Everything Electric roundup that triggered this (news note 260715 UK EVs Overtake Petrol and Solid State Batteries, private) — UK BEVs outsold petrol over the 12 months to May 2026; the solid-state and SMR claims
  • The V2G groundwork note (260910 V2G Home Power Grid Get Paid EV, private) — the bidirectional case in more detail
  • Race to Electrification — the vision this sits under
  • Electric Mobility and Liveable Cities — the transport-mode half
  • Climate Change — why the fuel source matters at all
  • Economic Instability — pump prices as the driver of adoption (petrol at a four-year high, September 2026)
  • The vault decision register (Decisions/index, vault-internal)

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