Monday morning, Hector yawns into his favorite Toyota for office. Start the car and keep his right hand on the steering wheel and left hand on the gear.
Try towing the car to get out of the garage.
Oh, no!
The gear won’t work, as it is already affected by the wrong oil. And he said to himself, “How can I forget this?”
Has it ever happened to you?
Choosing the right gear oil is tough when 75w90 and 80w90 sound the same. This is why everybody makes mistakes often.
But having a clear idea between 75w90 vs 80w90 will make the process easier. We’ll walk you through an in-depth analysis between these oils to define the best one.
Comparison Table Between 75w90 vs. 80w90
Nothing but a comparison table is worth fruitfully presenting the gist of these gear oils. So first let’s check a short but effective table.
| Features | 75w90 | 80w90 |
| Types | Synthetic | Synthetic |
| Used for | Gasoline engine | Diesel engine |
| Viscosity Index | 144 | 110 |
| Temperature range | -4°f to 300°f or -20°c to 176.667°c | -20°f to 400°f or -28.88°c to 204.44°c |
| Flashpoint | 410°f or 210°c | 431.6°f or 222°c |
| High temperature Resistance | Thinner so lower resistance | Thicker, so higher resistance |
| Fuel economy | Excellent | Good |
| Oil changing interval (Milage) | Every 50000 to 60000 miles | Every 12500 miles |
| Compatible vehicles | Passenger cars, Light-duty trucks, Final drives, Railway gearboxes | SUVs, 4WDs, Heavy-duty trucks, Agricultural equipment |
| Price | Little expensive | Affordable |
What Do 75w90 And 80w90 Mean In Gear Oil?
Most gear oils are formulated to fight against rust, corrosion, and oxidation. So it can maintain your vehicle’s axle machinery components under harsh weather and highly challenging situations.
But unless you know the exact meaning of 75w90 and 80w90. It seems nothing but a technical word to you. On the other hand, knowing the meanings of these words help you to clearly understand their purpose.
- In both of these cases, ‘W’ is the symbolic letter to define winter. The first digit indicates the temperature resistance in cold weather conditions, and the second indicates the temperature resistance in hot weather conditions.
- In other sense, the higher the difference between the two digits of the oil grade. The compatible temperature range for the oil will be higher. And vice versa.
- In the last sense, it also means the liquidity grade or the thickness of the oil. The higher number means, the thicker oil grade, and the lower number means the thinner oil grade.
That means the 75w90 grade gear oil is thinner and compatible to use in a wide range of temperatures.
The 80w90 grade oil is thick and excellent for high-temperature areas and heavy-duty towing trucks and SUVs.
A Quick Overview Of 75w90
75w90 oil mostly focuses on low-temperature regions, regular passenger cars, and light-duty vehicles. This is why the 75w90 oil is thin in the liquidity rate, which helps it flow faster throughout the gearbox, axles, and differential.
Besides that, this oil is fruitful to use in hot and cold weather conditions because of its wider temperature ranges. It can protect all the gearbox parts from engagement to reduce frictional damage.
Your vehicle will consume less fuel to run higher mileage. So you can enjoy smooth and long drives without facing frequent oil changes.
Advantages
- Enhance reliable lubrication to ensure protection
- Offer excellent film strength and long seal life
- Additional detergents provide superior thermal and oxidation stability
- Higher viscosity index reduces oil filling struggle
A Quick Overview Of 80w90
80w90 synthetic gear oil is thicker and formulated to use in hot weather conditions. Because your vehicle’s moving parts have to face more stress and pressure than in cold weather. More stress means smooth lubrication is required, and 80w90 can effectively meet that requirement.
This oil contains heat control and anti-wear additives to reduce gear wear and tear to prolong its efficiency and lifespan. So that 80w90 oil works better for heavy-duty and racing vehicles than light-duty vehicles on highways.
Though it works harder in high temperatures to offer protection and prevention, it comes at an affordable price, which won’t cut your pocket, instead put a smile on your lip.
Advantages
- Offer higher shear stability to withstand heavy loads
- Great to use on axles of spirals, gears, and some manual transmissions
- Excellent temp resistance to defend parts against corrosion
- Reduce fuel costs through affordable price
A Detail Comparison of 75w90 Vs 80w90
As all the gear oils are liquid and appear similar, it isn’t easy to distinguish. But, they have some core differences in formulation, thickness, implementation, and used components that won’t be visible.
But, without knowing those significant differences, you can pick the right gear oil for your vehicles. So let’s check out the detailed comparison.
Additional Additives
Though most gear oils are formulated from crude oil, they have added detergents for anti-friction and anti-wear. These additives enrich the oil’s quality and efficiency to protect against sludge and deposit buildup.
75w90
It comes with lower added detergents than 80w90 grade oil because it has to be incorporated with cold temperatures. But that doesn’t mean it is less effective and efficient for your vehicles. Instead, this 75w90 improves engine performance and durability.
80w90
It is a simple understanding that 80w90 oil is designed to use in high-performing and heavy-duty vehicles. It contains more additional additives to manage the high stress of your engine and keep it healthy.
Viscosity & Heat Resistance
In simple words, viscosity grade tells you about the oil’s thickness and heat handling capacity. The thin oil has a lower viscosity and is less temperature resistant. At the same time, the thick oil is high temperature resistant and has a high viscosity grade.
75w90
This oil is thinner in cold weather but turns thicker in hot weather. So, you can use it for both summer and winter. Its temperature range for cold weather is -4°f to -27°f and for hot weather, 300°f to 350°f.
80w90
As the oil is thicker, it can efficiently and effectively handle higher heat than 75w90. The temperature range for this oil is -20°f to 400°f. So you can confidently use this oil to protect your engine in extreme weather conditions.
High Mileage Efficiency & Oil Changing Interval
High mileage efficiency and oil changing interval of your vehicles are correlated. The higher the mileage efficiency the oil can offer, the longer the oil changing interval will be. And vice versa. So, we’ll discuss both things at one point.
75w90
As this oil is great to use in regular passenger cars and light-duty vehicles. So it won’t face that much struggle like 80w90 oil. This is why it comforts your vehicle with a smooth rotation of the moving parts. Consequently, you’ll get high mileage efficiency.
Most users of the oil recommend changing this oil every 50000 to 60000 miles or 80000 to 90000 kilometers. It has thriving mileage efficiency compared to 80w90.
80w90
High heat means harder working on your vehicle’s gearbox and axle parts and harder working on the gear oils. The harder the oil works, the lower its mileage efficiency.
You’ll get a maximum of 12500 miles or 20100 kilometers from the oil, which is around 4x times lower than 75w90. But, recognizing its high heat resistance level, you’ll find it worthwhile for your vehicles.
Load Capacity & Vehicle Types
Different types of vehicles are designed for different purposes and require different oils based on their working capability. Here, vehicle moving components and load handling capacity are significantly important in choosing the right gear oil.
75w90
Since it is a lighter oil and won’t reduce its properties in low temperatures, it is good to use in regular passenger cars for daily communication—lightweight trucks for carrying light loads. And lawnmowers for organizing your garden.
The philosophy behind the scene is these vehicles are run on city traffic, which is plain, less bumpy, and rocky. Even they are derived for a few hours at a time.
80w90
On the other hand, vehicles are designed for carrying heavy loads and running on highways. They work harder in a few sectors. Longer driving hours on bumpy, rocky, and muddy roads are common. In that case, the gearbox, accelerator, brake pedals, and all other mechanical parts work hard.
80w90 oil can handle all these vehicles’ stress and pressure like a champ to keep you stress-free.
Fuel Economy & Price
Oil consumption rate and its price walk hand in hand to define fuel economy. The lower oil consumption and the affordable price of the oil boost your fuel economy.
75w90
Your vehicle will consume less fuel due to regular use and less acceleration and braking. But, in terms of price, it is slightly more expensive than 80w90.
80w90
On the flip side, this oil is cheaper than 75w90 but consumes more fuel due to harder engine work.
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FAQs
Can I use 80w90 gear oil instead of 75w90?
Yes, you can use 80w90 gear oil instead of 75w90 because there is no significant difference between changing the oil. But, to get the maximum results and performance, it’s better to use the oil which meets your vehicle’s requirements.
Can I use 80w90 for a manual transmission?
Yes, you can use 80w90 for a manual transmission. As it can smoothly lube your manual transmission to protect it from immature wear and tear.
What To Choose Between 75w90 Vs 80w90?
Through our above discussion, we uplift the strength and weaknesses of 75w90 and 80w90 oils. But, it is not wise to announce one is better than the other without knowing your vehicle, engine types, weather conditions, and many other aspects.
You can choose 75w90 for regular passenger cars. As most of the time, you’ll drive it on city roads, and the low temperature is a suitable weather condition for this oil.
On the other hand, if you have a heavy-duty vehicle that loads heavy weight, and is driven on highways. You can go with 80w90 gear oil. However, above all, we will suggest you use manufacturer-recommended oils.
Hello, I’m Gary. Welcome to my blog.
Complete graduation from Weber State University ( Department of Automotive Technology)
I have been working with automotive for about 17 years. I have a garage in New Jersey.
In my spare time, I love to spend time with my family. Driving new cars is my hobby.