CarCareTruth Score
Decent, but it's tough on the environment.
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Prices may varyHealth score is for adult use as intended, per the manufacturer's SDS. It does not model child ingestion, accidental spill cleanup, or off-label use. See the safety panel below for full hazard classification, and /disclaimer for the full editorial scope.
GHS hazard codes are quoted from the manufacturer’s Safety Data Sheet. PPE tiers below translate those codes and the listed ingredient chemistry; they are not CarCareTruth recommendations.
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From the manufacturer’s Safety Data Sheet, Section 8
“H319 (eye irritation Cat 2) in SDS §2 · the concentrate pour from a squeeze bottle creates realistic splash risk at the tank fill neck.”
— Hot Shot's Secret
U.S. regulatory standard
29 CFR 1910.133(a)(1)
“The employer shall ensure that each affected employee uses appropriate eye or face protection when exposed to eye or face hazards from… liquid chemicals…”
ANSI Z87.1 (incorporated via §1910.6)
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
From the manufacturer’s Safety Data Sheet, Section 8
“H315 (skin irritation Cat 2) in SDS §2 · brief accidental drip contact during the standard tank-side pour.”
— Hot Shot's Secret
U.S. regulatory standard
29 CFR 1910.138(a)
“appropriate hand protection when employees' hands are exposed to hazards such as those from… chemicals which produce an adverse effect on the skin or eyes…”
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
From the manufacturer’s Safety Data Sheet, Section 8
“2-EHN at 50-75% with mixture-level H332 (harmful if inhaled). Outdoor pour adequate per SDS §8; garage or enclosed fueling area concentrates vapors from the aromatic naphtha and 2-EHN carrier.”
— Hot Shot's Secret
U.S. regulatory standard
29 CFR 1910.134(a); 1910.1200(f)
“The employer shall assess the workplace to determine if hazards are present, or are likely to be present, which necessitate the use of personal protective equipment.”
OSHA standards apply to workplaces. Cited here as the U.S. reference threshold for the underlying hazard class.
CarCareTruth publishes the cited sources verbatim and does not advise what action a user should take. Consult the full SDS before use.
No PPE specified in published sources for ventilation. Absence does not imply “not needed” — consult the full Safety Data Sheet.
PPE tiers translate the manufacturer’s SDS and U.S. regulatory standards. Not professional safety advice. How we report safety.
This product ranks #1 of 5 in Diesel Treatment.
Last reviewed June 14, 2026
TL;DR 2-EHN cetane improver confirmed in SDS §3 at 50-75% with strong community corroboration on idle smoothness and cold-start improvement, and it has earned a devoted following among diesel owners. Detergent and lubricity actives are trade secrets · the "6-in-1" claim cannot be independently verified beyond the cetane function. Health lands in the Serious Hazard band (4.2/10) from mixture-level H302 and H332 driven by the high 2-EHN concentration, plus Prop 65 listings for ethylbenzene and naphthalene.
EDT uses 2-ethylhexyl nitrate · the most independently studied cetane improver · at a concentration the brand describes as sufficient for up to a 7-point cetane boost. Higher cetane reduces ignition delay, smooths idle, and eases cold starts. The brand markets injector cleaning and lubricity protection through a proprietary package called LX4, but both actives are trade secrets with no independent test data. Community evidence is strongly positive: a genuine category favorite among diesel owners, with consistent reports of smoother throttle response after the first treated tank. Dose at 1-2 oz per 25 gallons at every fill-up from a graduated squeeze bottle. Not an anti-gel product · a separate EDT+ Winter Defense SKU handles cold weather.
Best for diesel owners running non-Top-Tier fuel who want a dedicated cetane boost at every fill-up. Skip it if your fuel already meets EN 590 cetane minimums from a Top Tier supplier, or if injector cleaning is the primary goal · the trade-secret detergent cannot be independently evaluated.
The SDS classifies this mixture with a WARNING signal word. H302 (harmful if swallowed) and H332 (harmful if inhaled) appear at the mixture level from the 2-EHN concentration at 50-75%. H373 (organ damage through repeated exposure) applies from the aromatic naphtha and xylene carrier fraction. SDS §15 lists Prop 65 warnings for ethylbenzene and naphthalene (both cancer). The concentrate pour into the diesel tank fill neck is the primary exposure window. Estimated VOC exceeds 550 g/L. Naphthalene carries documented aquatic toxicity at the ingredient level.
The label specifies 1 oz per 25 gallons for standard treatment, or 2 oz per 25 gallons for increased cetane and lubricity benefit. The 16 oz squeeze bottle treats up to 400 gallons at the standard rate. Pour directly into the fuel tank before filling.
The brand states it is designed for all diesel engines including Tier 4 compliant equipment. The ashless formulation avoids metallic-additive concerns. No documented community-reported compatibility issues have been found for CRDI or older mechanical injection engines.
No. EDT is a warm-weather and all-season maintenance treatment. For cold-weather anti-gel protection, Hot Shot's Secret offers a separate EDT+ Winter Defense product with wax-crystal modifier chemistry.
EDT is designed for every-fill-up maintenance dosing (1-2 oz per 25 gallons). Diesel Extreme is a concentrated one-tank deep-clean treatment for symptom-driven use · higher detergent concentration for severe injector fouling. They address different needs: EDT for prevention, Diesel Extreme for remediation.
The brand states that the cetane improvement from 2-EHN can improve fuel economy. Community reviews report modest MPG improvements, but results vary by engine, fuel quality, and driving conditions. Cetane improvement reduces ignition delay, which can contribute to more complete combustion.
Marketing copy from Hot Shot's Secret, via Amazon. Not editorial.
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