# Difference Between 87 Gas and 89 Gas Author: Nex Virox Team (Editorial Team) Reviewed by: Varshal Nirbhavane Published: 2026-09-04 Last updated: 2026-09-04 Canonical: https://nexvirox.com/difference-between/difference-between-87-and-89-gas/ **Quick answer:** The main difference between 87 Gas and 89 Gas is their octane rating, which measures fuel's resistance to engine knocking. 87 Gas is standard regular fuel with an octane rating of 87, while 89 Gas is mid-grade fuel with an octane rating of 89.

Difference Between 87 Gas and 89 Gas: Comparison Table

Aspect	87 Gas	89 Gas
Definition	Regular unleaded gasoline with an octane rating of 87.	Mid-grade unleaded gasoline with an octane rating of 89.
Purpose	Standard fuel for most everyday vehicles with standard engines.	Step-up fuel for engines that need more knock resistance.
Core Mechanism	Resists pre-ignition at compression ratios found in typical engines.	Resists pre-ignition under higher compression or hotter conditions.
Octane Rating	Pump octane number is exactly 87.	Pump octane number is exactly 89.
Combustion Speed	Burns faster under normal engine operating temperatures.	Burns at a slightly slower, more controlled rate.
Compression Tolerance	Knocks if compression exceeds standard engine limits.	Handles higher cylinder compression before knocking.
Energy Content	Contains roughly the same energy per gallon as 89.	Holds nearly identical energy per gallon as 87.
Fuel Economy	Yields no measurable mileage difference in engines designed for it.	Offers no real mpg gain unless the engine requires it.
Engine Power	Provides full rated power in engines tuned for regular.	Prevents power loss from knock in high-compression engines.
Engine Knock	Prone to knocking in high-performance or turbocharged engines.	Suppresses knocking where 87 would detonate prematurely.
Price per Gallon	Typically the lowest-priced fuel at the pump.	Usually costs a few cents more per gallon than 87.
Cost per Fill-Up	Cheapest option for a full tank of gasoline.	Adds a small amount to the total cost of a tank.
Engine Response	Delivers immediate throttle response in low-compression engines.	Provides smooth response in engines with advanced timing.
Detergents	Contains standard additive packages to clean injectors.	Often carries the same detergent package as regular.
Ethanol Content	Often contains 10% ethanol in many regions.	Typically also contains 10% ethanol in most areas.
Storage Stability	Degrades over months if left unused in a tank.	Degrades at a similar rate to 87 when stored.
Engine Longevity	Safe for engines designed to run on regular fuel.	Does not extend engine life beyond 87 in normal engines.
Vehicle Compatibility	Approved for most cars, trucks, and SUVs on the road.	Required only by vehicles that specify mid-grade fuel.
High-Altitude Use	Performs like higher octane at altitude due to thinner air.	Provides extra margin in naturally aspirated engines at altitude.
Turbocharged Engines	Risks knock and potential damage under boost.	Offers a safer margin for light turbo applications.
High-Performance Cars	Not recommended for sports cars with high compression.	Minimum acceptable grade for some performance vehicles.
Small Engines	Often recommended for lawnmowers and generators.	Acceptable but offers no benefit in small engines.
Older Vehicles	Matches the fuel spec for most pre-2000 cars.	Works fine but rarely needed in older standard engines.
Manufacturer Spec	Listed as required fuel in most owner's manuals.	Listed as minimum for select turbo or high-compression models.
Warranty Impact	Using it keeps most factory warranties fully valid.	Using it also keeps warranties valid where recommended.
Common Availability	Sold at virtually every gas station.	Available at most stations but often only one pump.
Typical Users	Everyday commuters driving standard economy vehicles.	Drivers of some trucks or cars that specify mid-grade.
Main Limitation	Knocks in engines demanding higher octane ratings.	Costs more while giving no benefit to standard engines.
Best-Fit Scenario	Best for daily driving in a stock, unmodified engine.	Best for engines that ping or knock on 87 gas.

What Is 87 Gas?

87 Gas is the standard regular unleaded gasoline sold at fuel stations across North America. It powers most everyday cars, trucks and SUVs by combusting in an internal combustion engine. It exists as the baseline, most affordable fuel option designed for engines with standard compression ratios.

Definition of 87 Gas

87 Gas is a petroleum-derived liquid fuel with a research octane number of 87, indicating its resistance to pre-ignition during compression. It is the minimum octane rating recommended by most automakers for vehicles without forced induction. Its chemical composition includes branched hydrocarbons that detonate predictably under normal engine operating conditions.

Key Characteristics of 87 Gas

Characteristic	What It Means in Practice
Octane rating	Rates 87, the lowest pump grade, meaning it ignites earlier under compression than higher octanes.
Cost efficiency	Typically costs 10-30 cents less per gallon than midgrade or premium fuels at the same station.
Compression tolerance	Handles compression ratios up to roughly 10.5:1 without causing engine knock in most stock engines.
Detonation resistance	Resists pre-ignition adequately for naturally aspirated engines but fails under high boost or heat.
Energy density	Contains roughly 114,000 BTU per gallon, nearly identical to higher octane fuels for equal volume.
Additive package	Includes detergents to clean intake valves, though often at lower concentrations than premium blends.
Ethanol content	Commonly blended with 10% ethanol (E10) in most regions, which lowers its effective energy slightly.
Availability	Sold at virtually every gas station, making it the most universally accessible fuel grade.
Engine compatibility	Approved for use in the vast majority of passenger vehicles built after 1990 according to owner manuals.
Knock threshold	Begins to knock or ping in high-performance or turbocharged engines when driven hard under load.

Common Examples of 87 Gas

Shell Regular - a widely sold 87 octane fuel with patented cleaning additives for deposit control.
Chevron Regular - uses Techron technology to reduce intake valve deposits in everyday commuter engines.
Exxon Regular - a standard 87 grade available at over 11,000 stations nationwide with Synergy additives.
Costco Regular - a Top Tier certified 87 fuel sold at warehouse prices, often discounted for members.
BP Regular - marketed as Invigorate formula, designed to clean engines and improve fuel economy.
Circle K Regular - a budget-friendly 87 option common in convenience store chains across North America.
Marathon Regular - a midwestern staple offering 87 octane with a proprietary detergent package.
7-Eleven Regular - a low-cost 87 fuel found in urban and suburban locations, often price-competitive.
Kroger Fuel Regular - a supermarket fuel with 87 octane, frequently paired with loyalty point discounts.
Sunoco Regular - an 87 grade sold in the eastern US, known for consistent quality and wide availability.

Advantages and Limitations of 87 Gas

Advantages	Limitations
Lowest price at the pump, saving the average driver roughly $200 to $400 annually versus premium.	Causes engine knock or pinging in turbocharged or high-compression engines that require higher octane.
Meets the minimum manufacturer requirement for most standard commuter vehicles, ensuring warranty compliance.	Delivers slightly lower fuel economy in engines that can adapt timing to use higher octane efficiently.
Universally available at every fuel station, eliminating the need to search for a specific pump grade.	Provides less protection against pre-ignition during extreme heat, heavy towing or sustained high-speed driving.
Produces adequate power output for everyday acceleration and highway cruising in standard engines.	Contains fewer detergents than premium grades, leading to faster carbon buildup on intake valves over time.
Reduces overall operating costs for fleets and high-mileage drivers who log thousands of miles monthly.	Performs poorly in performance vehicles, reducing horsepower and throttle response compared to 91 or 93 octane.
Compatible with flex-fuel vehicles when blended with up to 15% ethanol, offering flexible refueling options.	Can trigger check-engine lights in modern vehicles with knock sensors when the engine demands higher octane.
Lower refining cost translates to reduced carbon footprint during the production phase versus premium fuels.	Offers no benefit in engines specifically tuned for premium, and may cause long-term internal damage if used.
Works reliably in small engines like lawnmowers and generators that specify regular unleaded fuel.	Evaporates faster in hot climates, increasing the risk of vapor lock in older carbureted engines.
Provides consistent cold-start performance in winter months across most climate regions.	Lacks the octane headroom needed for aftermarket tuning, forced induction upgrades or track-day use.
Simplifies budgeting with predictable, stable pricing that rarely spikes as sharply as premium grades.	Produces more audible engine noise and vibration in engines designed to run on higher octane ratings.

What Is 89 Gas?

89 gas is a mid-grade gasoline with an octane rating of 89, positioned between regular 87 and premium 91 or 93. It resists engine knock better than 87 gas, making it suitable for vehicles that require mid-grade fuel or benefit from extra knock resistance under load.

Definition of 89 Gas

89 gas is a petroleum-based spark-ignition engine fuel with an anti-knock index (AKI) of 89, measured as the average of Research Octane Number (RON) and Motor Octane Number (MON). It contains detergent additives to prevent carbon deposit buildup and is formulated for engines specifying mid-grade octane.

Key Characteristics of 89 Gas

Characteristic	What It Means in Practice
Octane rating	89 AKI provides a middle ground between regular 87 and premium 91+, reducing knock risk in higher-compression engines.
Knock resistance	It withstands higher cylinder pressure before self-igniting, preventing the metallic "ping" sound during acceleration or uphill driving.
Energy content	Contains roughly 114,000 BTUs per gallon, nearly identical to 87 gas, so fuel economy differences are negligible in most vehicles.
Detergent package	Includes additives that clean intake valves and fuel injectors, helping maintain engine performance over time.
Ethanol content	Typically contains up to 10% ethanol (E10), which lowers its energy density slightly and can attract moisture in storage.
Volatility	Has a Reid Vapor Pressure of 9-10 psi, balancing cold-start performance with reduced evaporative emissions in warm weather.
Cost per gallon	Priced 10-20 cents higher than 87 gas, but 20-40 cents lower than premium grades, offering a moderate cost option.
Availability	Offered at roughly 40% of U.S. gas stations, though less common than regular or premium at smaller rural retailers.
Compatibility	Safe for engines designed for 87, but provides no measurable benefit unless the engine specifically calls for 89 or higher.
Environmental impact	Produces similar CO2 emissions to 87 gas per mile; no inherent environmental advantage over other gasoline grades.

Common Examples of 89 Gas

Shell V-Power Mid-Grade - Widely available at Shell stations, formulated with active cleaning agents to protect against engine deposits.
Chevron Supreme Mid-Grade - Uses Techron additive technology to clean fuel injectors and intake valves over extended use.
Exxon Synergy Mid-Grade - Designed to improve fuel economy and reduce emissions, available at most Exxon and Mobil stations.
BP Regular Plus - BP's mid-grade option, marketed with Invigorate additives that help prevent engine gunk buildup.
Costco Mid-Grade - TOP TIER certified, offering a cost-effective 89 octane option for members at warehouse prices.
Kroger Mid-Grade - Available at Kroger fuel centers, often discounted with loyalty points, meeting TOP TIER detergent standards.
Marathon Mid-Grade - Common in the Midwest, includes a detergent package that meets automaker cleanliness requirements.
Circle K Mid-Grade - Convenience store chain offering 89 octane, typically sourced from regional refiners with standard additives.
Sunoco Mid-Grade - Available in the Northeast and Mid-Atlantic, known for consistent quality and high-volume station throughput.
QuikTrip (QT) Mid-Grade - Popular in the South and Midwest, offering TOP TIER certified 89 octane at competitive prices.

Advantages and Limitations of 89 Gas

Advantages	Limitations
Reduces engine knock in vehicles that specify mid-grade fuel, preventing potential long-term engine damage.	Costs more than 87 gas without delivering any fuel economy or power benefit in engines designed for regular fuel.
Provides a safety margin for older engines with carbon buildup that raises effective compression ratio.	Less widely available than 87 or 91, potentially forcing drivers to detour or settle for a different grade.
Can improve performance in turbocharged engines that require higher octane but don't need premium's full rating.	Ethanol content can reduce fuel efficiency by up to 3% compared to pure gasoline, offsetting any perceived benefits.
Helps maintain smooth operation during heavy loads like towing or hauling in vehicles rated for 87.	No measurable reduction in CO2 emissions compared to 87 gas, so it offers no environmental advantage.
Offers a middle-cost option for drivers who want a slight knock-resistance buffer without paying premium prices.	Using 89 in a vehicle designed for 87 wastes money since the engine's knock sensor will never trigger to require it.
Compatible with all modern vehicles that accept 87, providing flexibility if premium is unavailable and 87 feels rough.	In vehicles requiring 91+, using 89 can trigger engine knock, reduced power, and potential warranty issues.
Often TOP TIER certified at major chains, ensuring detergent levels that prevent injector and valve deposits.	Storage stability is poor; 89 gas can degrade in as little as 3-6 months, making it unsuitable for long-term fuel storage.
Can extend spark plug life by reducing pre-ignition events that cause electrode erosion and misfires.	Higher price per mile than 87 in normal driving, with no measurable difference in miles per gallon for most engines.
Helps engines with high ambient temperatures maintain consistent performance, as heat increases knock tendency.	Not a "premium" product; it lacks the higher octane and sometimes enhanced additives found in 91 or 93 grades.
Provides a viable option for flex-fuel vehicles when E85 is unavailable, offering better fuel economy than ethanol blends.	Can cause confusion at the pump; drivers often mistakenly assume higher octane equals better fuel, leading to unnecessary spending.

Similarities Between 87 Gas and 89 Gas

Shared Aspect	How 87 Gas and 89 Gas Are Alike
Fuel Category	Both 87 gas and 89 gas are refined petroleum products classified as gasoline for spark-ignition internal combustion engines.
Primary Purpose	87 gas and 89 gas both serve to power vehicles by delivering controlled combustion energy to drive pistons.
Base Composition	Both 87 gas and 89 gas derive from crude oil and contain similar hydrocarbon chains, additives, and detergents.
Chemical Additives	87 gas and 89 gas both include corrosion inhibitors, anti-knock agents, and deposit cleaners mandated by regulators.
Combustion Process	Both 87 gas and 89 gas undergo the same four-stroke cycle: intake, compression, power, and exhaust.
Energy Density	87 gas and 89 gas each deliver roughly 114,000 BTUs per gallon, providing nearly identical thermal energy output.
Storage Requirements	Both 87 gas and 89 gas require sealed, grounded containers to prevent evaporation and static discharge.
Shelf Life	87 gas and 89 gas both degrade within 3–6 months when stored improperly, forming gums and varnishes.
Environmental Impact	Both 87 gas and 89 gas emit comparable CO2, nitrogen oxides, and particulates during combustion.
Fuel Economy	87 gas and 89 gas produce nearly identical miles per gallon in engines designed for either octane level.
Pump Delivery	Both 87 gas and 89 gas are dispensed from standard fuel pumps using the same nozzle sizes and flow rates.
Vehicle Compatibility	87 gas and 89 gas both work safely in the majority of modern cars with compression ratios below 10.5:1.
Cold Weather Start	Both 87 gas and 89 gas maintain adequate volatility for reliable cold-start performance down to -40°F.
Hot Weather Stability	87 gas and 89 gas both resist vapor lock and boiling in fuel lines at temperatures up to 140°F.
Detergent Levels	Both 87 gas and 89 gas contain the same minimum detergent concentration (TOP TIER standard) to clean intake valves.
Octane Measurement	87 gas and 89 gas both use the same (R+M)/2 method to calculate their anti-knock index rating.
Knock Resistance	Both 87 gas and 89 gas resist pre-ignition under normal driving conditions, though 89 offers slightly more margin.
Regulatory Standards	87 gas and 89 gas both meet ASTM D4814 specifications and EPA renewable fuel blending requirements.
Retail Availability	87 gas and 89 gas are both offered at nearly every gas station across North America, often from the same pump.
Taxation	87 gas and 89 gas both incur identical federal excise taxes (18.4¢/gallon) and state fuel taxes per gallon.
Ethanol Blend	Both 87 gas and 89 gas commonly contain up to 10% ethanol (E10) to meet renewable fuel mandates.
Lubricity Profile	87 gas and 89 gas both provide similar lubricity to fuel injectors and high-pressure pumps, preventing wear.
Emissions Systems	Both 87 gas and 89 gas are compatible with catalytic converters, oxygen sensors, and EVAP systems.
Maintenance Needs	87 gas and 89 gas both require the same routine maintenance: fuel filter changes every 30,000 miles and injector cleaning.
Warranty Coverage	87 gas and 89 gas both meet manufacturer minimum octane requirements for most standard warranty claims.
Safety Handling	Both 87 gas and 89 gas are equally flammable liquids requiring the same precautions: no smoking, static grounding, and spill containment.
Density Range	87 gas and 89 gas both fall within the same density range of 6.0–6.3 pounds per gallon at 60°F.
Flash Point	Both 87 gas and 89 gas have identical flash points around -45°F, making them equally volatile and hazardous.
Long-Term Storage	87 gas and 89 gas both require the same stabilizer additives (e.g., STA-BIL) to extend storage life beyond 12 months.
Performance Ceiling	87 gas and 89 gas both deliver identical peak horsepower and torque in engines tuned for regular fuel, with no measurable gain from 89.

87 Gas or 89 Gas: Which Should You Choose?

For most drivers, the one variable that decides it is your owner's manual. If it says regular fuel, 87 Gas is correct, and 89 Gas adds cost without benefit. Choose 89 Gas only when your engine specifically requires it or you notice knocking.

When to Use 87 Gas

Choose 87 Gas when your owner's manual recommends regular unleaded, which covers most standard cars. Use it for daily commuting, highway driving, and older vehicles without turbochargers. It is also the right choice for budget-conscious drivers seeking the lowest cost per gallon.

When to Use 89 Gas

Choose 89 Gas when your manual explicitly requires mid-grade fuel, often for high-compression engines or turbocharged models. Use it if you hear persistent engine knocking or pinging on 87 Gas. It also suits small engines like lawnmowers or generators where the manufacturer demands it.

Common Misconceptions About 87 Gas and 89 Gas

Common Myth	The Reality
87 gas is lower quality fuel that will damage my engine over time.	87 gas meets the same ASTM standards as 89 gas, so it will not damage a standard engine.
89 gas always contains more cleaning detergents than 87 gas.	Detergent additives vary by brand and station, not by octane rating, so 89 gas is not inherently cleaner.
Using 89 gas in a car designed for 87 gas boosts horsepower.	89 gas only prevents knock; it adds no power unless the engine is tuned for higher octane.
87 gas is the same thing as regular unleaded, so it is always the cheapest option.	87 gas is regular unleaded, but its price varies by region, station, and market conditions.
89 gas burns hotter than 87 gas, so it provides better fuel economy.	89 gas has a similar energy content per gallon, so fuel economy differences are negligible in most cars.
Mixing 87 gas and 89 gas in the tank will cause a dangerous chemical reaction.	Mixing 87 gas and 89 gas is safe; the blend simply results in an intermediate octane rating.
89 gas is required for all turbocharged engines, and 87 gas will cause pre-ignition.	Most modern turbo engines run fine on 87 gas; 89 gas is only needed if the owner's manual specifies it.
87 gas has more ethanol than 89 gas, which reduces its overall quality.	Ethanol content is typically 10% in both 87 gas and 89 gas, so the octane rating does not affect ethanol levels.
89 gas will make my car start faster in cold weather than 87 gas.	Cold-start performance depends on vapor pressure and additives, not the octane difference between 87 gas and 89 gas.
87 gas is only for older cars, while 89 gas is for newer vehicles.	Car age does not determine octane need; the engine's compression ratio and tuning dictate the requirement for 87 gas or 89 gas.
89 gas gives a smoother idle and reduces engine vibration compared to 87 gas.	Idle smoothness is controlled by the engine management system, so 87 gas and 89 gas perform identically in normal conditions.
87 gas will cause more carbon buildup in the combustion chamber than 89 gas.	Carbon buildup results from incomplete combustion and oil, not from the octane level of 87 gas versus 89 gas.
89 gas is a premium fuel that extends the life of spark plugs and oxygen sensors.	Spark plug and sensor life depend on combustion quality and maintenance, not on choosing 89 gas over 87 gas.
87 gas is less refined than 89 gas, so it contains more impurities.	Both 87 gas and 89 gas come from the same refining process; octane is adjusted with additives, not by purity.
89 gas will prevent engine knocking in any car, even one that requires 87 gas.	89 gas prevents knock only if the engine is prone to it; a healthy engine on 87 gas will not knock.
87 gas evaporates faster than 89 gas, so it goes stale quicker in storage.	Evaporation rates are similar for 87 gas and 89 gas; storage life depends on sealed containers and stabilizers.
89 gas is better for towing heavy loads because it provides more torque.	Towing performance depends on engine load and gearing, not on the octane difference between 87 gas and 89 gas.
87 gas will cause my check engine light to come on if I use it regularly.	The check engine light triggers from sensor faults or misfires, not from using 87 gas in a car that accepts it.
89 gas has a higher energy density, so it gives more miles per gallon than 87 gas.	Energy density is nearly identical for 87 gas and 89 gas, so mileage gains are not a real benefit of 89 gas.
87 gas is only sold at discount stations, while 89 gas is sold at premium brands.	Both 87 gas and 89 gas are sold at all station types; brand reputation does not change the octane chemistry.
89 gas will reduce emissions and help my car pass an emissions test.	Emissions are controlled by the catalytic converter and engine tune, not by choosing 89 gas over 87 gas.
87 gas causes more engine noise, like ticking or pinging, than 89 gas.	Engine noise comes from mechanical parts or low oil, not from the octane rating of 87 gas versus 89 gas.
89 gas is a mid-grade fuel that is always a blend of 87 gas and 93 gas.	89 gas is often blended at the pump, but it is a distinct product, not a simple mix of 87 gas and 93 gas.
87 gas will void my car warranty if the manual recommends 89 gas.	Using 87 gas when the manual requires 89 gas can void a warranty, but only if it causes documented engine damage.
89 gas is better for high-altitude driving, while 87 gas causes vapor lock.	At high altitude, lower octane like 87 gas is often fine; vapor lock is a heat issue, not an octane issue.
87 gas has a shorter shelf life than 89 gas, so it degrades faster in a lawnmower.	Both 87 gas and 89 gas degrade at similar rates; fuel stabilizers matter more than the octane rating for storage.
89 gas will improve throttle response and acceleration in a standard commuter car.	Throttle response is set by the engine computer, so 89 gas offers no measurable improvement over 87 gas in a stock car.
87 gas is a low-grade fuel that lacks the lubricants found in 89 gas.	Neither 87 gas nor 89 gas contains engine lubricants; lubrication comes from the engine oil system.
89 gas is safer for the environment than 87 gas because it burns more completely.	Both 87 gas and 89 gas produce similar emissions; environmental impact depends on the vehicle, not the octane rating.
87 gas will cause my fuel injectors to clog faster than 89 gas.	Injector clogging comes from dirt or poor fuel quality, not from the octane level of 87 gas versus 89 gas.

Conclusion

Difference Between 87 Gas and 89 Gas comes down to octane rating and engine knock resistance. 87 suits standard engines; 89 benefits high-compression or turbocharged models. Check your owner’s manual first. Choose 87 for economy and everyday driving. Choose 89 only if your vehicle requires it or knocks on 87.

## FAQ ### What is the difference between 87 gas and 89 gas? The difference is the octane rating, where 87 gas has an octane rating of 87 and 89 gas has an octane rating of 89, indicating 89 gas resists engine knocking more effectively than 87 gas. ### Which is better for my car, 87 gas or 89 gas? The better choice depends on your engine's compression ratio, but 89 gas is better for high-compression engines that require mid-grade fuel, while 87 gas is better for standard engines that run efficiently on regular fuel. ### Is 89 gas more expensive than 87 gas? Yes, 89 gas typically costs 10 to 20 cents more per gallon than 87 gas, reflecting the higher octane content and additional refining processes required to produce mid-grade fuel. ### Can I use 89 gas instead of 87 gas without damaging my engine? Yes, you can safely use 89 gas instead of 87 gas in most vehicles, as higher octane fuel won't damage standard engines, though it may reduce fuel economy slightly and provide no performance benefit. ### What happens if I accidentally put 87 gas in a car that requires 89 gas? If you put 87 gas in a car requiring 89 gas, the engine may experience knocking or pinging under load, but modern engine control units will adjust timing to prevent damage, though performance and fuel economy will temporarily decrease. ### Does 89 gas give better gas mileage than 87 gas? No, 89 gas does not inherently provide better gas mileage than 87 gas, as fuel economy is determined by engine design and driving conditions, not octane rating, unless your engine is specifically tuned to take advantage of higher octane. ### What is the octane rating of 87 gas and 89 gas? The octane rating of 87 gas is 87, and the octane rating of 89 gas is 89, measured using the anti-knock index, which represents the average of the research octane number and motor octane number. ### Can I mix 87 gas and 89 gas in the same tank? Yes, you can mix 87 gas and 89 gas in the same tank, as the resulting octane rating will be between 87 and 89, roughly proportional to the mixture, and this is safe for most engines. ### Is 89 gas better for high-performance vehicles than 87 gas? Yes, 89 gas is better for high-performance vehicles with turbocharged or high-compression engines, as the higher octane rating prevents pre-ignition and knocking, allowing the engine to maintain optimal power output and efficiency. ### Should I switch from 87 gas to 89 gas for a long road trip? No, you should not switch from 87 gas to 89 gas for a long road trip unless your owner's manual specifically recommends mid-grade fuel, as the higher octane won't improve highway fuel economy or performance in standard engines.