When detailers and mobile car wash operators compare steam car wash machines, the first number they usually check on the spec sheet is steam pressure (bar).
Here’s the short answer: Pressure alone doesn't tell the whole story. To evaluate cleaning performance and daily capacity, consider it alongside temperature, steam flow rate, and moisture control.
Same 8.5 Bar. Why Does Steam Output Differ?
Two models can have the same pressure but deliver different maximum steam flow rates. OPTIMA STEAMER's diesel XD and XDm models and electric XE 12K and XE 27K models all operate at 8.5 bar (123 psi) and a maximum pressure of 9.5 bar (138 psi). The key difference is their maximum steam flow rate.
Note: Compare the XD and XDm on the OPTIMA XD vs OPTIMA XDm comparison page
Here’s how the models compare:
OPTIMA XD (Diesel)
• Steam flow rate: 300–1,800 cc/min
• Preheating time: 3–4 min
• Steam outlet valves: 2
OPTIMA XE 12K (Electric)
• Steam flow rate: 300–900 cc/min
• Preheating time: 10–11 min
• Steam outlet valves: 2
OPTIMA XE 27K (Electric)
• Steam flow rate: 300–1,700 cc/min
• Preheating time: 6–7 min
• Steam outlet valves: 2
OPTIMA XDm (Compact Diesel, for Mobile Detailing)
• Steam flow rate: 250–500 cc/min
• Preheating time: 3 min
• Steam outlet valves: 1
The steam flow rate range on a spec sheet indicates how much the output can be adjusted between dry and wet steam settings. For example, the OPTIMA XD delivers approximately 300 cc/min on its dry steam setting and up to 1,800 cc/min on its wet steam setting. If you clean several vehicles back-to-back or have two operators working simultaneously, pay close attention to the maximum steam flow rate and the number of steam outlet valves.
※ Model tested: OPTIMA XD
Check Steam Temperature at the Gun Tip, Not Just the Boiler
To evaluate the heat delivered during cleaning, check the steam temperature at the gun tip. The boiler temperature of our main models ranges from 174–178°C (345–352°F), while steam temperature at the gun tip reaches up to 135°C (275°F), according to the official OPTIMA STEAMER website. High-temperature steam helps loosen grease and grime, while steam pressure helps remove the loosened dirt from the surface.
Temperature also changes with spray distance. Based on our in-house measurements, temperatures were 85°C (185°F) at 5 cm (2 in) and 74°C (165°F) at 10 cm (4 in). Always test on a small, inconspicuous area before cleaning vehicle paint, leather, or protective films.
※ Model tested: OPTIMA XD | Ambient temperature: 18°C (64°F), tested indoors
Can You Adjust Dry and Wet Steam?
Moisture control allows a single machine to adjust steam output for both exterior and interior cleaning. However, always test on a small area before cleaning sensitive materials. Every OPTIMA STEAMER model has a moisture control valve. This valve sets the moisture content of the steam. Open the valve when you need wet steam. Close it when you need drier steam, such as for vehicle interior cleaning.
Read the Spec Sheet in This Order
1. Power Requirements: Confirm your site's voltage, phase, and electrical capacity. Diesel models need single-phase power; electric models need three-phase power.
2. Maximum steam flow and steam outlet valves: Match them to your daily vehicle volume and number of operators.
3. Gun tip temperature and moisture control: Match them to your main job: exterior, interior, or engine bay.
4. Preheating time: This affects start-up time and the wait before restarting.
5. Pressure (Bar): Check operating and maximum pressure last.
Safety is equally important. Do not modify the manufacturer's pressure or temperature settings. Steam cleaning can be noisy, so wear appropriate hearing protection, safety glasses, and protective gloves. Do not spray directly at radios, speakers, displays, or exposed electrical components inside the vehicle. Do not use diesel models in enclosed spaces. When operating indoors, make sure the area is well ventilated.
FAQ: Does Higher Pressure Mean Better Cleaning?
Pressure is only one factor that affects cleaning performance. Even at the same pressure, results change with steam flow, temperature, and moisture settings. The best way to compare performance is to test different machines on the same vehicle under similar cleaning conditions.
The Bottom Line
Steam pressure (bar) is just a starting point. Consider steam flow rate, gun tip temperature, moisture control, preheating time, and power requirements together to find the right model for your needs.
Use our diesel and electric model guide to identify your requirements. Then contact our sales team for a detailed consultation before making your decision.
※Diesel and electric model guide: https://www.sjecorp.com/board/news/board_view.php?page=1&num=4644
CONTACT US: sales@sjecorp.com
