Our published methodology for sourcing, tagging, and verifying every claim on this site - including what we count as verified, what we don't, and how we handle corrections when we get something wrong.
Every number on this site is tagged to its source. We never publish untagged claims. If you can't trace a figure back to a specific data source, it doesn't go on the page.
[EM-VERIFIED] to [PLACEHOLDER] - each with a published meaningFull methodology, tag definitions, and how we handle mistakes, below.
We source data from four primary channels, each with a specific purpose and a corresponding data tag.
24,650 unique quote requests across all brands in 2025, including 9,000+ Jaguar-specific enquiries. This is the backbone of every failure rate, cost range, and decision split we publish. [EM-VERIFIED]
Direct conversations with 100+ UK engine specialists who regularly rebuild Jaguar engines. This is where we get the mechanic's-eye view that raw data can't show. [EM-INTERVIEW]
Customer satisfaction data collected 3-6 months after replacement. This is where we learn whether owners were glad they made the choice they did. [EM-SURVEY]
Manufacturer TSBs, Auto Trader, Parkers, and other publicly available UK market data. We cite the source and date with every use. [THIRD-PARTY]
Every number on this site carries exactly one of these seven tags. No untagged claims are allowed to ship.
| Tag | Meaning | Source |
|---|---|---|
[EM-VERIFIED] | Exact count or percentage from our internal CRM | 24,650 quote requests, Jan–Dec 2025 |
[EM-QUOTE] | Pricing ranges from actual supplier quotes sent through our CRM | Supplier quotes + interviews |
[EM-SURVEY] | Post-sale customer survey results | 100+ surveys 3-6 months after replacement |
[EM-INTERVIEW] | Direct statements from mechanics, workshop owners, or supplier managers | Hundreds of conversations 2024-2025 |
[THIRD-PARTY] | External data from named, dated sources | Auto Trader, Parkers, manufacturer TSBs, etc. |
[PATTERN DATA] | Documented expert-knowledge claim, no proprietary volume behind it | Workshop consensus / market observation |
[PLACEHOLDER] | Needs sourcing before publish - does not ship | - |
Verification is a three-stage process. Stage 1: Tagging. Every number is tagged to its source at the point of writing - not after. If a figure can't be tagged, it doesn't go in. Stage 2: Expert review. Every page is reviewed for factual accuracy by a member of our expert panel before publication; their role is to catch technical errors, not to approve editorial stance. Stage 3: Public correction. When we make a factual error, we correct it and log the correction publicly in our corrections log - with the date, the page, the error, and the corrected text.
We distinguish between factual errors (wrong numbers, misattributed claims, incorrect dates) and updates (new data that supersedes older figures). Factual errors go in the corrections log with a clear acknowledgement of the mistake. Updates are noted on the page itself, but do not require a correction log entry unless the update changes a previously published claim in a materially significant way. Our full data methodology is published in full, including what we count as a failure and what we don't.
When we make a factual error, we correct it. That sounds obvious, but the bar is higher than most sites set: we log every correction publicly in our corrections log, with the date, the page affected, the error, and the corrected text. We do not silently fix errors without acknowledgement.
We also publish a corrections log that is linked from every page on the site. If you spot an error that we haven't logged, we want to hear about it - our contact page has details on how to reach us. Our editorial standards set out the full policy, including how we handle disputes about what constitutes a factual error versus a difference of interpretation.
Just as important as what we publish is what we don't. We never publish:
Where a claim requires a number that isn't in our primary data, we mark it [ESTIMATED] and use relative language - "typically", "many owners", "a common pattern" - rather than presenting it as a verified fact. This is a deliberate choice: we'd rather be seen as honest about our limits than caught out for overclaiming.
This site is free to use because specialists pay us for the enquiries we send them. You pay us nothing, and we take no commission on the work itself. We'd rather explain that openly than let you assume the site runs on goodwill.
And it's precisely why our data verification matters: if we only ever told people to replace their engine, we'd generate more enquiries in the short term and destroy the reason anyone trusts us in the long term. That's why our repair vs replace framework is published in full - including the 60% threshold above which we tell people not to replace - and why pages like is it worth replacing an X-Type engine and when should you scrap a Jaguar exist at all. We lose an enquiry every time we tell someone to scrap their car. We publish the framework anyway. Our full editorial standards and specialist vetting criteria are also published in full.
Seven Data Tags, PublishedEvery number traces to a source. No untagged claims.
Three-Stage VerificationTagging, expert review, and public correction - not a single checkbox.
Public Corrections LogWe log our mistakes openly, not silently correct them.
Commercial Model DisclosedSuppliers pay for enquiries. You pay nothing. Stated plainly.
Our full methodology, editorial standards, and specialist vetting criteria are published on the pages below.
FULL DATA METHODOLOGY EDITORIAL STANDARDS