---
title: "Reviews — 5w40 engine oil - Flapen"
canonical_url: "https://flapen.com/research/uk/automotive/5w40-engine-oil/reviews"
last_updated: "2026-08-07T13:22:17.412Z"
locale: en
meta:
  description: "Niche score 50/100 · £188K/yr market · 119K searches/yr · £23.02 avg price. Strong incumbent ratings (4.8★) keeps it on the watch list. Data updated Jul 2026."
  "og:description": "Niche score 50/100 · £188K/yr market · 119K searches/yr · £23.02 avg price. Strong incumbent ratings (4.8★) keeps it on the watch list. Data updated Jul 2026."
  "og:title": "Reviews — 5w40 engine oil - Flapen"
---

# **5w40 engine oil**

**Worth a look**

Shows low returns (0.6%), but strong incumbent ratings (4.8★) keeps it on the watch list.

Market size 38Growth 49Conversion 74Competition 37Returns 97Price range 78Avg price 95Brand share 17Review moat 48Quality gap 15

**Returns**

**Incredible****0.6%**

return rate — above 5% kills the launch gate

**Avg price**

**Incredible****£23.02**

avg listing price — sweet spot $15–$100

**Price range**

**Great****£7.44–£42.20**

cheapest to priciest tracked listing — scored on the share inside $15–$100

**Conversion**

**Good****6.8%**

search→purchase rate — share of searches ending in a sale

**Growth**

**Okay****+19.2%**

90-day search growth — must beat 0% to launch

**Review moat**

**Okay****1,728.29**

avg incumbent reviews — the moat a new listing must climb

**Market size**

**Okay****£188K**

£188K/yr · 119K searches

**Competition**

**Okay****63%**

top-5 click share — leaders hold, buyers still browse

**Brand share**

**Bad****93%**

top-5 brand share — brand-locked demand

**Quality gap**

**Bad****4.8★**

avg incumbent rating — lower means beatable quality

## Reviews