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SMi™ 'Stepper Motor' Gauges

AccuTech™ SMi™ Oil Pressure Gauge
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AccuTech™ SMi™ Oil Pressure Gauge
Part #: 52-46540
Gauge / Tach Options
'Stepper Motor' Racing Gauges
The next generation in instrumentation

SMi™ Stepper motor gauges use a small electronic motor that only turns a tiny fraction of a rotation to drive the pointer. It is electronically controlled and is much more precise than the traditional mechanical instruments whose accuracy can be affected by many factors. Many professional race teams - NASCAR™, etc. – are switching to this style of gauge for the improved accuracy (see the in-car cameras). Approved for use by IMCA™.

Built-in Warning Lights – Ultra Bright 2 Stage LED
2 set points are easily adjusted to your needs (critical oil pressure has 3 set points). For example set water temp for just above normal running temp (if you run 215° set it at 230°). Above that the LED comes on to let you know the motor is starting to get warm. Set the second one at the max temp your engine can tolerate (say 250°). At this point the LED flashes to attract your attention, possibly saving motor damage.

Since oil pressure is so critical it has 3 set points.
You can set the first just below normal running pressure (say normal is 60 psi – set it at 50 psi – no damage there). At this point the LED comes on. Set the second at 35 psi. The LED flashes – you need to know here, possible damage. Set the third at 20 psi. Engine damage is likely here. At this third set point the LED continues to flash PLUS the gauge backlight starts to flash. It’s hard to miss this – day or night. It allows you to get the engine shut down before it blows up, saving you $$.

  • Gauges are 2-5/8” and have a molded polycarbonate / ABS case (virtually unbreakable)
  • An electronic sensor (incl.) is installed on the motor to drive the gauge - no oil or fuel in the driver’s compartment for safety.
  • Thru-the-dial LED backlights and an illuminated pointer make these easy to read at any speed
  • ”Presentation” at turn-on - Gauges go through a self test. Pointers swing full scale and all LEDs come on
  • Quick & simple to install - Connect power to one gauge and ‘daisy chain’ the others to it (wiring included). Connect the sensor wire and you’re done
  • Can be used with 12 & 16 Volt negative ground systems with or without an Alternator
  • 0-100 PSI


NOTE: These electronic gauges are not intended to be waterproof. Cover the gauges if the car interior is to be washed down.

Weather Resistant SMi™ Gauge option available (choose above when ordering)

  • Silicone sealed to resist moisture (don't direct pressure wash)


California Proposition 65 Statement


Brand: AccuTech™ SMi™
Style: Stepper Motor
Type: Electronic Oil Pressure
Size: 2 5/8" diameter
Case Material: Polycarbonate ABS
Face Color: Black
Bezel Color: Black
Pointer Color: Red LED illuminated
Range: 0-100 psi
Sensor Included: Yes
Wiring Included: Yes - 5' lead length
QD 'Pigtail' Wire Included: Yes
Sensor Adapter Included: No
Sensor Fitting Size: 1/8" NPT
Gauge Backlights: Blue
Gauge Warning Lights: Yes
Run on 12v System: Yes
Run on 16v System: Yes
Power Draw: 61mA @ 12v
Weather Resistant: Option available
Replacement Parts
Pressure Sensor - 100 psi: PN 43520
QD 'Pigtail' Wire: PN 43530
Wire Harness: PN 43534
Pressure Sensor Adapter: PN 43525


AccuTech™ SMi™ Gauge Overview

AccuTech™ SMi™ Oil Pressure Warning In-Car Video Testimonial

This last race some debris came up and knocked the dry sump belt off the pump. Thanks to my new Longacre SMI gauges I got her shut down in time before destroying my motor. The oil pressure gauge blinks like crazy when the third warning setting goes off. Thankfully that got my attention in time to shut her down. Now we are just looking at new bearings and a light polish job.

I think that with the pressures of running up front in a big race I would have missed the little warning light on my old mechanical gauge set.

Thank you SMI Gauges!
Gary Lewis

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