Part# 08-00048-12
MFR Model# UREM40E-12PK



Aviation Spark Plug With the most automated manufacturing processes and the most innovative spark plug in the aviation industry. Made in USA.

High Conductivity Copper Core Center Electrode copper, co-extruded inside a nickel alloy sleeve ensures outstanding heat and electrical conductivity while the nickel sleeve offers high resistance to corrosive combustion gases.

High Alumina Ceramic Insulator high mechanical strength, superior dielectric properties, proprietary protective glaze, provides high performance to conquer severe operational conditions. "Clean Collar" massive electrode "V" tip focuses heat to reduce fouling and enhance heat range control.

Proprietary Glass Center Seal 21st century 'fired in' resistor replaces the multipart screw, spring, carbon pile stack up used in competitive plugs and known to suffer from resistance value instability that can cause misfires, wasted fuel, engine roughness.

Nickel Finish environmentally preferable electrolytic nickel provides outstanding durable finish, superior corrosion protection, and extreme wear resistance.

Nickel Ground Electrodes aviation grade nickel electrode design focuses on minimizing sparking voltage requirements while maintaining specification gaps to ensure large, stable 'flame kernels' for on-time ignition and complete combustion.

Vacuum Infused Center Electrode proprietary, vacuum infusion process seals electrode/insulator gap providing stable heat range and superior center electrode cooling (heat flow to the insulator).

Hot-Lock Assembly intense pressure and heat create positive, zero-leakage, shrunk in seal between insulator and shell to contain the hot, high pressure combustion cycle gases.

Harness Wire Contact smooth, uninterrupted, oxide treated spring contact surface offers enhanced corrosion resistance, is chemically bonded to the fired-in resistor providing the ultimate harness/spark plug termination integrity and energy transfer.

Application Guide

  • Frequently Purchased With
  • Customers Also Viewed


These Tempest plugs were ordered as replacements for my current plugs which are getting worn. The current batch has given me flawless service

Art H Verified Purchase


February 5, 2022

So far, so good. Nicer finish than Champion.

William S Verified Purchase


January 27, 2022

Great plugs

Miguel A Verified Purchase


August 24, 2021

I would definitely use Tempest Aviation Spark Plugs. Performed a resistance ohms test (using a volt/ohm meter) and found all the plugs with the manufacturers limits. Checked a Champion plugs that were installed previously and found several with resistance over 5K ohms (over 5K ohms can damage magnetos and ignition wires) whereby the Tempest plugs averaged 1.2K ohms.

Herschel C
June 28, 2021

Quick delivery, good price.

Ronald L
May 5, 2021

The plugs showed up promptly. They replaced the worn-out Champion plugs in my A-65, and I’m pleased with the Tempest plugs’ performance to date.

March 29, 2021

Installed on Cessna 150 O-200

Travis R
March 16, 2021


Morandini A
January 27, 2021

Items arrived promptly, well packed and exactly what I ordered.

William B
January 21, 2021

Spark plugs were great

Jerry P
December 13, 2020


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: Does Tempest provide the copper gasket on the UREM40E? Or purchased separately?

Each Tempest spark plug will come with one copper gasket. Any additional gaskets must be purchased separately.

Q: Is the Tempest UREM40E the equivalent of the Champion REM40E? I hope so as I have just ordered 8 UREM40E's?

Yes, the Tempest UREM40E is a direct replacement for the Champion REM40E. Both with work in the same applications.

Q: What size copper gasket is required with the Tempest UREM40E plugs, 14 or 18mm?


Q: The Champion chart calls for a REM40E in a Continental W-670 while Tempest calls for a UREM38E. Why does Tempest call for a colder plug in the same application?

The heat ranges actually overlap each other. You can use either one.

Q: What size is the UREM40E? 5/8 or 3/4 ?

5/8 inch.

Q: Is a fine-wire plug available for the UREM-40E?

UREM38S is the fine wire version of UREM40E.

Q: Does the Tempest UREM40E gap come pre-set?

Yes, these will come pre-gapped within a certain range. The end user will need to verify with their application on what gap they are actually needing. The massive plugs are gapped .016" to .021" and the fine wire are .017 to .021".

Q: Are Tempest UREM40E spark plugs identical in dimensions as the Champion REM40E? The cowling has bump outs for the spark plugs so the dimensions are critical for proper clearance.

Yes, the physical dimensions are the same for both brand plugs.

Q: Are these Tempest UREM40E plugs considered "Long reach" spark plugs?

These are not. UREM37BY would be considered long reach.

Q: Are all the Tempest spark plugs direct replacements for the Champion plugs minus the leading U on the part number. ( is a UREM38E, a direcct replacemet for the Champion #REM38E?)

Yes, they are equivalent applications and interchangeable.