Can 98 and 95 gasoline be mixed?

2 Answers
SanBrady
07/24/25 12:15am
95 gasoline and 98 gasoline can occasionally be mixed, but it is not recommended to mix them for a long time. The following is a specific introduction about gasoline: Long-term mixing of gasoline can cause engine knock. Gasoline is a mixture. The gasoline grade usually referred to is the anti-knock index (i.e., octane number) of gasoline. Strictly speaking, 95 gasoline and 98 gasoline cannot be mixed. However, their chemical compositions and other aspects are relatively similar, with strong anti-knock properties. To ensure vehicle safety, they should still be used separately. Some regions still have low-grade 90 gasoline. Mixing it with high-grade gasoline can cause knocking, insufficient power, and other phenomena. It will also affect the service life of spark plugs and bring more exhaust pollution. The density of 98 gasoline is generally above 0.74. 98 gasoline is gasoline whose octane number is equal to a mixture of 98% isooctane and 2% n-heptane. The advantages of 98 gasoline are "two highs and two lows," namely higher anti-knock performance and power performance, and lower harmful substances and exhaust pollution in the gasoline. 95 gasoline has strong anti-knock properties and will not be compressed and ignited under high pressure, ensuring the engine is at the optimal ignition timing, and the power output is not affected. The gasoline grade also represents the anti-knock performance of the fuel. The higher the grade, the better the anti-knock performance. Anti-knock performance refers to the ability of gasoline to resist knocking when burning in the engine. It is the primary indicator of gasoline combustion performance. Knocking is caused by abnormal combustion of gasoline in the engine. The octane number is precisely the target of gasoline's anti-knock performance. The higher the octane number, the stronger the anti-knock performance. The higher the compression ratio, the higher the pressure in the combustion chamber. If gasoline with low anti-knock performance is used, knocking is more likely to occur.
Was this review help?
2
2
Share
MacKyle
08/10/25 8:03pm
I remember once driving to a remote area where the gas station only had 95 octane fuel, while my car usually takes 98. I ended up mixing a full tank. It turned out okay—the car didn’t stall—but I noticed the acceleration felt slightly sluggish, and the engine sound was rougher than usual. Mixing gasoline averages the high octane of 98 with the mid-octane of 95, and the car’s ECU tries to adjust the ignition timing to prevent knocking, but this might not be optimal. Over time, it could lead to more carbon buildup or sensor issues. Later, I checked the manual, which recommends using only the specified fuel grade. Mixing is fine in a pinch but shouldn’t be done long-term. Now, I always plan my gas stops in advance to avoid such hassles. After all, the engine is the heart of the car, and proper maintenance ensures it runs smoothly and reliably for the long haul.
Was this review help?
11
0
Share
Expand All
More Forum Discussions

What Causes Oil Filter Leakage?

The reasons for oil filter leakage are: a broken sealing gasket, not tightening it properly during installation, or overtightening which may cause the housing to crack. During engine operation, metal shavings, dust, carbon deposits oxidized at high temperatures, gummy deposits, water, and other contaminants continuously mix with the lubricating oil. The oil filter's function is to remove these mechanical impurities and gum, keeping the lubricating oil clean and extending its service life. An oil filter should have strong filtration capability, low flow resistance, and a long service life. Typically, the lubrication system is equipped with several filters of different filtration capacities: the oil strainer, coarse filter, and fine filter, which are connected in parallel or in series within the main oil passage.
16
1
Share

What type of vehicle is the Jetta VS5?

Jetta VS5 is a compact SUV, with dimensions of 4419mm in length, 1841mm in width, and 1616mm in height, and a wheelbase of 2630mm. In terms of exterior design, the front face of this car adopts Volkswagen's X design elements, extending bidirectionally to the hood and lower grille. The side profile features lines that continue the Volkswagen brand design, running through the entire body. For the powertrain, this car is equipped with a 1.4-liter turbocharged engine across all variants. This engine delivers a maximum power of 110 kW, a maximum torque of 250 Nm, with the maximum power achieved at 5000 to 6000 rpm and the maximum torque available from 1750 to 3000 rpm.
15
4
Share

How many seats does the Mercedes-Benz GLE have?

The Mercedes-Benz GLE is available in both five-seat and seven-seat configurations. The GLE is a mid-size to large SUV with dimensions of 4941 mm in length, 2018 mm in width, and 1782 mm in height, and a wheelbase of 2995 mm. In terms of powertrain, this model is equipped with two engine options: a 2.0-liter turbocharged engine and a 3.0-liter turbocharged engine. The 2.0-liter turbocharged engine delivers maximum power at 6100 rpm and peak torque between 1800 to 4000 rpm. The 3.0-liter turbocharged engine achieves maximum power between 5500 to 6100 rpm and peak torque between 1600 to 4500 rpm.
3
4
Share

How to Reset the Maintenance Light on the Tayron?

Tayron maintenance light reset method: While pressing the maintenance button, turn the ignition key to the light-on position. After hearing a beep, release the maintenance button, wait for two seconds, then press and hold the minute button next to the instrument panel. Check if the maintenance light has been cleared. If it has, the reset was successful; otherwise, repeat the above two steps. The original purpose of the car maintenance light is to remind the owner to perform maintenance as soon as possible. After maintenance is completed, the 4S shop will use a fault diagnostic tool to reset the vehicle's maintenance light. The Tayron has a length, width, and height of 4589mm, 1860mm, and 1660mm respectively, with a wheelbase of 2731mm. In terms of configuration, in addition to conventional features such as a 360-degree panoramic image, third-generation intelligent parking assist system, and blind spot detection, this vehicle is also equipped with a traffic jam assist system.
5
5
Share

How to Turn on High Beam in Mercedes-Benz?

Method to turn on high beam in Mercedes-Benz: Push the left-hand stalk towards the driver's side to activate the high beam. Release the stalk, and it will automatically return to its original position. Pull the stalk back to turn off the high beam and switch back to low beam. The high beam improves visibility and expands the field of view. On dark roads without streetlights, the visible range with high beam is much farther than with low beam alone, making it essential to use high beams in such conditions. The Mercedes-Benz S-Class has dimensions of 5209 mm in length, 1872 mm in width, and 1473 mm in height, with a wheelbase of 3165 mm. In terms of power, this model is equipped with four types of engines: a 2.0-liter turbocharged engine, a low-power 3.0-liter turbocharged engine, a medium-power 3.0-liter turbocharged engine, and a high-power 3.0-liter turbocharged engine.
20
2
Share

What does the 'V' on car tires indicate?

Car tires marked with 'V' indicate that the maximum speed under load is 240 kilometers per hour. This letter represents the speed rating of the tire. Tires with higher ratings are more expensive but offer better performance and safety. Typically, compact family car tires have lower speed ratings, while high-performance sports car tires have higher ratings. Spare tires are categorized into full-size spares and temporary spares. Full-size spares are identical to the original tires, whereas temporary spares are only meant for short-term use. Car tires are one of the most important components of a vehicle, as they directly contact the ground and, together with the suspension system, help absorb shocks during driving, ensuring comfort and stability. High-quality tires provide excellent grip between the wheels and the road, enhancing traction and drivability.
19
1
Share
Cookie
Cookie Settings
© 2025 Servanan International Pte. Ltd.