Background:
Someone brought my attention to the SprogTech ST-X intake, and advised me that a series of impressive claims are being made about the intake.
I checked out the product description and then contacted the vendor to ask about the availability of the Dyno results on which they were basing some of their claims.
That was a dead end, but this presents an opportunity to use the product as an example to help consumers be aware when making purchase decisions.
Product Claims:
Some of the key performance benefits attributed to the intake are highlighted in the following list of excerpts from the product page:
- Performance rivalling some of the biggest, most popular brands of intake on the market.
- Huge reduction in intake air temperatures over an open air / ‘heat shield’ intake
- Massive integral velocity stack optimising airflow
- The fully enclosed design will ensure heat soak is completely minimised.
- In the case of the EA8-C (carbon), heat soak will be almost non-existent.
- We have seen no loss in performance whatsoever,
- the STX-EA8 performed better than almost any other intake kit on the market, when we conducted back-to-back dyno testing
- a massive 100mm inlet and some trick airflow manipulation allow this kit to perform as well as anything currently available.
- It’s the last 10% of design that you just don’t see in other products on the market,
- Without question, there is nothing that offers this level of performance for this money,
I inquired about the dyno results and was told:
Although we have done dyno testing with other kits when we were developing our STX kit, we are unable to provide direct comparisons between our kit and others, as it is not good practice since we also sell some of these other brands.
If an individual wants to conduct their own independent testing, they are more than welcome to do so.
What I can say is when we conducted our testing, our STX made the same power and a little more torque as a very popular enclosed kit from one large manufacturer and made around 8bhp more than a very popular open intake kit from another large manufacturer. Knowing how well these kits perform when tested against others, and having spoken to a number of UK tuners which confirm these results, we know how well-placed our kit is on the market and the performance it offers when comparing it to more expensive / well established kits.
Sprogley Motorsport
Claims Analysis:
Reviewing the claims and justifications will be the subject of the remainder of this post.
Vague & Unverifiable Performance Comparisons
Advertising Claims:
(1) “Performance rivalling some of the biggest, most popular brands of intake on the market. Even at high power levels!”
(7) “STX-EA8 performed better than almost any other intake kit on the market, when we conducted back-to-back dyno testing.”
Business Explanation:
“We are unable to provide direct comparisons between our kit and others, as it is not good practice since we also sell some of these other brands.“
Key Issues:
- The claim suggests superiority without naming the competing products or providing data.
- They refuse to substantiate the claim, citing a conflict of interest—yet they publicly made the claim in the first place.
- A back-to-back dyno comparison should have logged intake temps, power gains, and other engine data —yet no evidence is shared.
- Considering UK Advertising Guidelines, such an unsubstantiated claim could be false advertising.
Sales Tactic:
They imply customers must accept the claim on faith or conduct their own independent testing, shifting the burden of proof to the buyer.
Misleading Statements About Heat Soak
Advertising Claims:
(4) “The fully enclosed design will ensure heat soak is completely minimised.“
(5) “In the case of the EA8-C (carbon), heat soak will be almost non-existent.”
Key Issues:
- Absolute language (“completely minimised”, “almost non-existent”) is misleading.
- Carbon fiber has low thermal conductivity, which can reduce heat transfer, but it does not eliminate it.
- Heat soak depends on multiple factors: engine bay temp, heat transfer from the turbo, ambient conditions, and vehicle operation.
Sales Tactic:
No data (intake air temperature (IAT) comparisons) is presented. This creates an unrealistic expectation that cannot be scientifically validated.
Unverifiable Dyno Gains & Appeal to Authority
Business Explanation:
- “Our STX made the same power and a little more torque as a very popular enclosed kit from one large manufacturer and made around 8bhp more than a very popular open intake kit from another large manufacturer.”
- “Having spoken to a number of UK tuners which confirm these results, we know how well-placed our kit is on the market.”
Key Issues:
- They provide no actual dyno sheets, conditions, or test methodology details.
- Power gains from intakes alone are typically minor unless significant airflow restrictions exist.
- Appeal to Authority Fallacy—mentioning unnamed “UK tuners” as validation without citing data.
Sales Tactic:
- They imply other experts agree, but without proof, this is meaningless.
- The burden of proof is again shifted to the customer.
Emotional Persuasion & False Superiority
Advertising Claims:
(8) “Some trick airflow manipulation allows this kit to perform as well as anything currently available.“
(9) “It’s the last 10% of design that you just don’t see in other products on the market.”
(10) “Without question, there is nothing that offers this level of performance for this money.”
Key Issues:
- Vague technical jargon (“trick airflow manipulation”) with no specifics.
- Implies hidden superiority (“last 10% of design”) but does not explain what makes their product unique.
- Extreme claim (“nothing offers this level of performance for this money”)—which is unverifiable without comparative data.
Sales Tactic:
- Uses hype instead of measurable proof.
- Suggests a “hidden advantage” that competitors lack—without explaining it.
Conclusions:
The claims in the advertising description for the SprogTech ST-X intake and the explanations provided by the business present several issues for consumers. These include:
- Unverified Superiority Claims – The business asserts dominance over competitors but refuses to provide the necessary comparative data.
- Lack of Evidence – Despite stating they have conducted back-to-back tests, they do not share results, making the claims empty marketing rhetoric.
- Shifting Burden of Proof—Instead of providing data, they tell consumers to conduct their own tests. The seller should be responsible for proving the product’s effectiveness.
- Misleading Heat Soak Claims – Absolute statements about “minimised” or “non-existent” heat soak are not scientifically validated.
- Appeal to Authority Without Evidence – Mentioning “UK tuners” as validation is meaningless without supporting test data.
Consumer defenses:
Some ways that consumers can protect themselves when considering products for purchase are to:
Ask for data: If a company claims back-to-back testing, demand dyno sheets, IAT logs, and test conditions.
Be wary of absolute claims: “Completely minimised” and “nothing else offers this performance” are red flags of exaggerated marketing.
Recognize emotional persuasion: If they can’t explain why their product works better with actual numbers, it’s probably just hype.