Mosselman Oil Thermostat N54/N55 (E-Series)Mosselman Turbo Systems is a Dutch manufacturer of high quality performance parts designed specifically for use in BMW and MINI cars. Mosselman has been in the tuning business for over 40 years and the vast majority of their products has been designed, tested and manufactured in house. If you own a BMW or MINI, they are a specialist in these makes. PRODUCT INFORMATION THE NEXT LEVEL OF TEMPERATURE CONTROL The N54, N55 and S55 engines are no strangers
Mosselman Turbo Systems is a Dutch manufacturer of high-quality performance parts designed specifically for use in BMW and MINI cars. Mosselman has been in the tuning business for over 40 years and the vast majority of their products has been designed, tested and manufactured in-house. If you own a BMW or MINI, they are a specialist in these makes.
PRODUCT INFORMATION
THE NEXT LEVEL OF TEMPERATURE CONTROL
The N54, N55 and S55 engines are no strangers to oil cooling problems, that’s why we recommend installing the MSL Oil Thermostat, especially for cars that are tuned. The standard oil temperature will reach around 120°C (250°F) with a normal driving style. The MSL Oil Thermostat will open at a lower temperature than the standard oil thermostat (at 85°C / 185°F) and will keep the temperature stable between 95 and 105°C (200 and 220°F), depending on the car model.
Installing the MSL thermostat ensures a cooler oil temperature which will result in more stable performance, but above all this improves the reliability of the engine. It is equipped with a real thermostat, not an always open solution. The oil will still reach the operating temperature at the same time as a stock thermostat.
Installation instructions are included in kit
Suitable for E82 135i Coupe, E88 135i Convertible, E82 1 Series M (1M), E90 335i Sedan, E91 335i Touring, E92 335i Coupe, E93 335i Convertible and E89 Z4 35i & 35is Roadster models fitted with N54 or N55 engine.
MSL OIL THERMOSTAT
A highly recommended upgrade for N54, N55 and S55 engines.
20°C Lower Than Stock Operating temperature 20°C lower than stock.
Rock Solid Housing CNC machined housing.
Real Thermostat Equipped with a real thermostat, not an always open solution (for use in hot and cold climates).
Quick Installation
The Thermostat is plug-and-play and made out of a solid block of high-grade aluminum at Mosselman's own facility. It is equipped with a real thermostat, not an always open solution. The oil will still reach the operating temperature at the same time as a stock thermostat.
Additionally to the thermostat, Mosselman have oil cooler kits for the 1-Series E8x and the 3-Series E9x. We advise the Oil Cooler Kit for cars that use the full performance of the car during track use. The kits are available as single or twin cooler kits. The single cooler kit replaces the OEM cooler on the right side of the car, the twin kit will add an extra cooler on the left side of the car.
EXPERT'S ADVICE:
"The N54 engine is no stranger to oil cooling problems, that’s why we recommend installing the MSL Oil Thermostat. The standard oil thermostat will reach around 120 degrees Celsius with a normal driving style. The MSL Oil Thermostat will open at a lower temperature than the standard oil thermostat (at 85 degrees Celsius) and will keep the temperature stable between 95 and 105 degrees Celsius, depending on the car model. Installing the MSL thermostat ensures a cooler oil temperature which will result in more stable performance, but above all this improves the reliability of the engine. It is recommended to install the thermostat, especially for cars that are tuned.
The Thermostat is plug-and-play and made out of a solid block of high-grade aluminium at our own facility. It is equipped with a real thermostat, not an always open solution. The oil will still reach the operating temperature at the same time as a stock thermostat.
Note: The Oil Thermostat Installation kit prevents the Oil Thermostat from leaking and is highly recommended when installing the MSL Oil Thermostat. The kit includes 2 x O-ring for the oil hose and 1x rubber oil filter housing gasket. We advise to add it to your order."
MARK HENDRIKX - AUTOMOTIVE ENGINEER AT MOSSELMAN
FREQUENTLY ASKED QUESTIONS
Does the MSL Oil Thermostat have a real thermostat?
Yes, it is equipped with a real thermostat, not an always open solution. The oil will still reach the operating temperature at the same time as a stock thermostat.
Do I need new gaskets for the installation?
Yes, we highly recommend replacing the gasket and 0-rings to prevent the thermostat from leaking. We have an installation kit available, it includes 2 x O-ring for the oil hose and 1x rubber oil filter housing gasket. We advise to add it to your order.
Installation Time
The thermostat is plug-and-play, which means that you don't have to make modifications to install the thermostat. Just remove the old one and replace it with our MLS Oil Thermostat. The installation time will be approximately 30 minutes.
Models
1 Series / E82 / E88 (2007-2013) / 1 Series M (1M)
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Reviewed in the United States on October 17, 2025
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ChelaTho813
Lexington, US
★★★★★ 5
The only one I'll use!
As the title says, this is the brand to get!! It's fast-acting, doesn't give me weird dreams like some do, and I never wake up feeling groggy.
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Reviewed in the United States on March 13, 2025
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Belle of the Ball
Cuba, US
★★★★★ 5
Works wonders
I've been buying these for well over a year now as Subscribe and Save. I work 12 hour overnights as a nurse. My sleep schedule normally gets messed up. I would have no problem falling asleep but would wake up only a few hours later which is not good when you have work again that night. We buy these on Amazon due to the great price and the fact that they are extended release which helps keep me asleep longer. When I take 1 or 2 of them, I am able to sleep about 7-8 hours which is great. I take this both when I sleep during the day and sleep during the night. It helps me sleep no matter when and I am able to adjust my sleep schedule often. I have recommended them to many.
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Reviewed in the United States on January 10, 2013
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PSBone
Pawtucket, US
★★★★★ 4
Works quite well, dose still a bit high for me
Used to take the Natrol 5mg slow release, now that I can compare these 2, I love this more. It doesn't make me feel too edgy, it's quite relaxing actually. I still have to halve the dose as the full dose makes me groggy the next day. Where the Natrol gave me very vivid, but not unpleasant dreams, these don't make me dream as vividly. It does take a bit longer to get me to sleep, but once asleep, your asleep. Highly recommend, once I finish this bottle, I'd get the 2mg tr next time, as a lower dose works better for me.
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Reviewed in the United States on July 10, 2014
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Eudy Ernesto De León Batista
Fort Morgan, US
★★★★★ 5
Excelente Muy Satisfecho
Servicio excepcional, cuidadoso, el producto muy bien empacado. Y el tiempo de entrega fue el acordado. Y del producto ni hablar, excelente.
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