In short
Act 31-2007, as amended, establishes that every advertisement of new automobiles shall include, at a size no smaller than one quarter (1/4) in proportion to the prominence of the model’s name or price, the miles-per-gallon yield, both in the city and on the highway, as determined by the Environmental Protection Agency (EPA) and the federal Department of Energy. The Department of Consumer Affairs shall have the powers necessary and convenient to issue regulations and take the pertinent administrative actions to guarantee compliance with this Act, and it shall be the Secretary’s duty to amend the regulation on deceptive practices and advertising to carry out its purpose. The statement of motives explains the reason: miles-per-gallon yield is one of the relevant factors when selecting a motor vehicle, and the EPA and the federal Department of Energy coordinate annually to publish a guide with that figure. The Act itself explains what the two numbers mean: the “city” concept represents trips in urban areas, in which a vehicle is started in the morning after being parked all night and travels during high-traffic hours; the “highway” concept represents the combination of trips on rural roads and expressways, generally in light traffic. The Act took effect one hundred twenty (120) days after its approval.
What is it?
It is an advertising rule, not a manufacturing one: it does not tell the dealer which car to sell, it tells them what must appear in the ad and at what size. What makes it useful is precisely the size: the law is not satisfied with the figure being present, it requires it to be legible in proportion to the name or the price.
Who can do it?
It applies to every advertisement of new automobiles in Puerto Rico. The law speaks of “new automobiles”: it does not extend the duty to used ones.
Requirements
- That it be an advertisement of new automobiles.Verified against the official source
Documents you need
Information pending verification.
Cost
Step by step
Step 1: Both numbers must be there
One is not enough. The law requires “the miles-per-gallon yield, both in the city and on the highway.” An ad publishing only the highway figure — almost always the higher one — does not comply.
Step 2: The size is part of the duty
Here is what makes this law different. The figure must be included “at a size no smaller than one quarter (1/4) in proportion to the prominence of the model’s name or price.” That is: the bigger the price appears in the ad, the bigger the mileage must appear. Fine print at the bottom does not comply.
Step 3: Where the numbers come from
The dealer does not invent them. The yield is that “determined by the Environmental Protection Agency (EPA) and the federal Department of Energy,” which per the statement of motives coordinate annually to publish a guide with the new models’ mileage.
Step 4: What “city” and “highway” mean
The law takes the trouble to define them, and it is worth reading before comparing two ads. The “city” concept represents trips in urban areas, in which a vehicle is started in the morning after being parked all night and travels during high-traffic hours. The “highway” concept represents the combination of trips on rural roads and expressways, generally in light traffic.
Step 5: Who enforces it
The Department of Consumer Affairs “shall have the powers necessary and convenient to issue regulations and take the pertinent administrative actions to guarantee compliance with this Act.” And without constituting a limitation, the Secretary has the duty to amend the regulation on deceptive practices and advertising to carry out the law’s purpose.
Where to do it
The Department of Consumer Affairs is the agency this law designates to enforce it, through its regulation on deceptive practices and advertising. The step by step of the complaint is in our DACO complaint guide. If your problem is not the ad but the vehicle you already bought, that is the motor vehicle warranties guide; if it is the repair shop invoice, that has its own.
How long it takes
What to do if something goes wrong
A defect in the text that must be said. The compilation names TWO different regulation numbers for the same regulation. The law’s opening summary says the Secretary must amend “Regulation No. 7231 Against Deceptive Practices and Advertising”; the statement of motives and Article 2 both say “Regulation No. 6672 on Deceptive Practices and Advertising.” We report both numbers and choose neither. The Act appears amended by Act No. 119 of July 17, 2008, the likely origin of the mismatch, but the compilation does not say so and we do not assert it. What we did not read and therefore do not publish: Regulation 6672, Regulation 7231, Act 5-1973 (DACO’s organic act), Act 119-2008 itself, and the EPA and federal Department of Energy mileage guide. So this guide publishes no fine figure — Act 31-2007 sets no penalty in its text — and no mileage figures for any model. Processing time is left unverified for the same reason.
Common mistakes
- Looking only at the highway number: the law requires city and highway in the same ad.
- Accepting the figure in fine print: it must be no less than 1/4 of the prominence of the name or price.
- Believing it applies to used cars: the law speaks of “new automobiles.”
- Assuming the dealer calculates the mileage: the EPA and the federal Department of Energy determine it.
- Comparing one ad’s city figure with another’s highway figure: they are different scenarios, and the law defines them.
- Expecting a fine in this Act: it sets none; the route is DACO’s regulation.
Frequently asked questions
Must the ad state the miles per gallon?
Yes. Every advertisement of new automobiles shall include the miles-per-gallon yield, both in the city and on the highway, as determined by the EPA and the federal Department of Energy.
How big must it appear?
At a size no smaller than one quarter (1/4) in proportion to the prominence of the model’s name or price. It is not a fixed size: it depends on how large the name or price appears in that ad.
Does it apply to used car ads?
The law speaks of “new automobiles.” We read no provision extending the duty to used cars, so we do not publish that it applies to them.
What fine applies for non-compliance?
Act 31-2007 sets no penalty in its text. What it does is empower DACO to regulate and take administrative actions, and require the Secretary to amend the regulation on deceptive practices and advertising.
Official sources
These are the government pages this guide is based on.
- Departamento de Asuntos del Consumidor (DACO)
DACO
bvirtualogp.pr.gov
- DACO services
DACO
www.daco.pr.gov
Last verified
August 24, 2026
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