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May 16, 2017

By David Murphy

Over the last several years, well actually ever since they've been released, we've received countless questions on the ISSPRO EV2 series of gauges. That's not unexpected; they are the most popular aftermarket gauges for the diesel performance enthusiast.  Of all the questions we get, I'd like to address the most frequently one asked, and that is, "what's the difference between EV1 and EV2 gauges"?

Before I get into the litany of the differences here, I'd like to first discuss some of the reasoning for the release of the newer EV2 series gauges.

History Lesson

Back in 2008 ISSPRO sought the need to come out with a new gauge series, one that would have more modern features as well as offer them better control over their supply chain for the necessary components. At the time their best selling gauges were the Enhanced Visibility (EV) series.

Upon its release in 2000, they had decided to dub it the Enhanced Visibility series because this gauge offered through-the-dial (TTD) backlighting. TTD backlighting is simply just what it sounds like. The lettering and numbers light up from behind the gauge's dial due to the silk-screening process used for the numerals. This TTD backlighting has been used in all modern cars and trucks for well over 40 years.

The EV Series was far superior to their Standard Product line, which used an older style of perimeter lighting. Perimeter lighting is best described by a plastic ring around the outer part of the dial.  This ring gathers light from the gauges rear mounted lamp, and in turn casts down some of this light onto the gauge and reflects off its specially painted numerals on the dial.

The EV Series was a great improvement over the Standard Product line.

ISSPRO decided that unlike many of their competitors that were using TTD lighting, they wanted to ensure that their new gauge line didn't have any dark spots on the dial.  A problem in the past with TTD lighting is that the lamps in the back of the gauge couldn't shine light onto the entire face of the gauge (picture a rear projection television, circa 1980's). If there was anything in the way of this light transmission, like a circuit board, then obviously the light can't shine through it, and therefore there will be dark spots on the dial at night. To accomplish better TTD lighting they opted to remove most of the circuitry from the electric gauges in the series and house these components in a small, external, plastic enclosure that they call a driving circuit box, or amplifier (AMP) box.

The use of this amp box has been a concern for many customers in the past, primarily because they think that it requires more installation work. It actually doesn't though. The amp box is already pre-wired, so that all the installer has to do is connect the amp box cable to the back of the gauge's pig-tail connector. With the circuitry removed from the guts of the gauge, ISSPRO was able to accomplish the use of effective TTD backlighting unlike any of their competitors. On their mechanical gauges, like Turbo Boost, Air Pressure, Fuel Pressure, etc., there is no need for an amp box because there isn't any circuit board in the gauge to begin with.

Enter the EV2 Series

As time went on, as it has a tendency to do, some of the competition already started using LED TTD backlighting and stepper motor driven needle movements in their offerings. The use of stepper motors and LED backlighting allows for great space savings. In LED lighting alone, the improvements have been tremendous each year compared to the last. We now have brilliant color billboards, LED televisions, LED headlights that are now competing with the best High Intensity Discharge (HID) lamps. We also have eye-watering, skin-blistering LED flashlights that make laughable the old, heavy, and large D-cell powered, pinnacle torch of the past.  Yes I said torch I have some British blood in me, sorry.

It was no surprise to me when Curt Bourgoine, the Aftermarket Sales Manager at ISSPRO, asked to meet with me to find out what recommendations I might have on a new product line for the company. I won't boor you with the details, but I think it's safe to say that many of my recommendations were taken into consideration in now what we call the EV2 series. I'm just glad they finally decided to call it EV2 and not some of the other names they were kicking around. I don't think I could ever sell a gauge called the "Private Label" series. Just the name makes me think of pouring a Johnnie Walker Black on the rocks.

The use of a stepper motor driven needle, compared to the EVs air-core movement, does not really equate into a more accurate gauge, but rather the improvement is in the space savings. Don't read into what I just said there. I'm by no means saying or even implying that the stepper motor EV2 is less accurate, but rather I haven't seen any difference in accuracy over one from the other. I mention this because I know of some manufacturers that tell their customer that the use of a stepper motor driven needle movement is more accurate.  I think not, but that's my opinion take it for what it's worth.  And while we're on the topic of space savings, the use of LEDs are where the EV2s really shinesorry, I couldn't resist. LED's are small, brilliant, and come in many colors. No longer is there a need for placing the circuitry outside of the gauge housing. The LED's are installed internally, not on the rear of the gauge like in the older EV and Standard series gauges. Because of the LEDs small size and increased life-span, they are located in the gauge right behind the dials. No dark spots and no bulbs to ever replace.

Cosmetics EV2 Series Not Just Another Pretty Face

Looks are everything when it comes to instrumentation. That's a fancy word for gauges, not that horn you played in band class back in elementary school. ISSPRO has sought to really go after the "factory matched" market with their EV2 series. They have factory matched gauges for the 1st 2nd 3rd and now 4th generation Dodge Ram trucks, 1994-1997 Ford trucks,  the 1999-2005 Ford Superduty, 2011-newer Superduties, the 2007-Up GM Duramax, 2014-2015 Dodge Ram STD, the 1999-2010 VW Jetta, and even the 2016 Nissan Titan XD. Everyone wants gauges that look like they belong in their truck, and the EV2 lineup has something for just about everyone.  The dials for the 2010-2013 4th Gen Dodge Ram are actually manufactured by the same supplier that makes the dials for Dodge.

At the time of me putting fingers to keyboard typing this article, ISSPRO has nineteen different styles of EV2 gauges. They come in all different dials, bezels, lighting, and pointer configurations. We've done a video on all of the different styles which can be found on the DieselManor YouTube page if you want to see more. As far as the common features, the EV2 series all have a flat scratch resistant glass lens that is fog proof.  That's important because the last thing you want is to have your gauges fog up on you.  I actually had another name brand of US made gauges in an overhead gauge mount in my truck years ago before the EV2 series was available, and they fogged up on me the fist time I took the truck out of the garage. I already had a pyrometer, boost, and trans temp gauge in the EV series mounted in an A-pillar pod, but I wanted some other gauges that just weren't available in the EV line, so I opted for another brand.  Once the EV2 series was released I ordered up a set to replace my fog-prone overhead gauges, and they have been running flawlessly ever since, and ohh yes, the older EVs have been running fine too, since 2002.

With its connector plugged in to its back, the EV2s require just 1-5/8" of mounting depth, which makes installing them in small gauge pods like the steering column mounts, simpler. The EV2s don't come with a mounting bracket, but rather they have a well thought out alternative. They all have six small barbs on the back of the gauge housing that cause the gauge to snap into place and provide for the proper tension in the 2-1/16 mounting holes found in most gauge mounts. If required, ISSPRO does offer and optional mounting bracket kit, part number R19999, that will allow for a tighter fit in the rare occasion that it's necessary to secure the gauge in an oversized gauge opening.

The LED lighting in the EV2 series is brilliant and crisp. Dimming can be a nuisance at times if you want to dim them beyond about half brightness.  The types of LEDs they use don't lend themselves to dimming very well. At about the halfway point on your factory dimmer the EV2s will start to flicker, and if you dim them any more they go out.  That's just the nature of LEDs. Like most people I rarely dim my gauges, I just don't find a need for it. If dimming your gauges to the point where they're barely visible is important to you, then I would suggest you look the older EV series that uses incandescent bulbs that lend themselves to dimming very well. This dimming problem isn't just with ISSPRO EV2s. Auto Meter gauges with LED backlighting do it as well.  (On edit: I've been told that all 2015 and later produced EV2 gauges have improved dimming characteristics that allow for lower light output without the flicker).

The pointers on the EV2s are fantastic. One thing I dislike on my EVs is that their pointers don't light up as brilliantly as they do on the EV2s that I have.  During the daytime my EVs are perfect. They gather ambient light and cause the pointer to brighten up just as well as any fiber optic gun sight. At night the same cannot be said though.  The red pointers just don't match the intensity of my factory dash gauges. They do get brighter; they just don't match as well.  I've sold myself on this shortcoming by telling myself that the gauges in my pillar wont be too distracting by having overly bright pointers that close to my eyes. For the most part I've bought it.

Cosmetics EV Series

When it comes to looks the original EV series still offer something that will accommodate the vast majority of people looking for a sharp looking gauge for their ride. The EV series does not have as many styles to choose from. They are offered in just 4 styles. The first being a black dial, black bezel, white numerals, and white pointer with black a needle hub.  At night the numerals will light up white. The second is the same with the exception of the pointer, which is red. Both of these styles can be fitted with optional colored bulb covers that will allow you to change the backlighting color of the numerals to green, blue, or orange.  The third style has a white dial, black bezel, black numerals, and a red pointer with a white needle hub. At night the numerals will light up turquoise-green. The last is what they call the Marine Series. It features a white dial, chrome bezel, blue numerals, and a blue pointer with a black needle hub. All of the gauges have pointers that will light up in their respective color.  All EVs sport a convex, polycarbonate, scratch resistant lens; that is also fog proofed prior to assembly. As mentioned earlier, I have a set of these on the pillar and I've had them there for over 15 years now. Not once have they ever fogged up on me.  

Lighting is serviced by either 1 or 2 incandescent bulbs mounted in the back of the gauge. These bulbs will cast the proper amount of light onto the back side of the dial, producing crisp visibility of the numerals and tick marks. Due to the nature of regular incandescent bulbs, dimming is flawless. These gauges can be dimmed along with your factory gauges perfectly. As stated, the 2 gauge styles that have black dial's can be fitted with colored bulb covers to provide a different contrast for the numerals. I personally like the use of the green ones. I've found that they cause the correct shade of green to match my factory instruments.  A little trick I've learned over the years is to use a colored Sharpie marker to add a little more color to the bulb if you find that the illumination isn't green or blue enough. You just draw a few lines on the bulb with the marker and then apply the colored bulb cover over it.

The EVs also come with a removable o-ring behind the rim of the bezel. While most people will just remove this prior to installation, it can be used to frontally seal the gauge for applications where water and moisture may be present. ISSPRO actually sells some of their EV gauges to boat manufacturers (read Marine Series) and when they're mounted in a console that may come in contact with water, this feature is a necessity. I've found that the convex (slightly domed) lens actually reflects less glare than a flat lens. The overall length of the EVs are 2-7/8" with the o-ring removed, but that's taking into consideration the length of the 2 threaded studs for mounting bracket. I've found that the use of the included mounting bracket is unnecessary, so to give me more room inside the tight confines of most gauge pods, I just cut approximately 1 inch of the studs off. The gauges simply press-fit into most mounting holes, and therefore fit snuggly in place. As with the EV2 series, and many other gauges, occasionally the mounting holes may already be too loose to allow for the gauge to fit tightly. While this is a rare occasion, I've found that putting a little masking tape around the gauge will provide the right friction fit to allow the gauge to be secured adequately, without the need for the mounting bracket. Of course if you want, you can always use the mounting bracket. Just make sure you don't trim the threaded studs down before determining whether or not you'll need to use them. The mounting brackets are secured by two knurled thumb nuts.

Wiring the EV2 Series

ISSPRO has really done their homework on the wiring considerations for the EV2 series. All gauges utilize the same orange connector on the back. This six-pin, low-profile connector, really makes wiring a quick process. All EV2s have their power, ground, and illumination wires in the same pin locations on their connectors.  All you need to do is use the supplied hook-up wire and press the wire through the opening in the connector that corresponds to the wire that you are connecting. If you're installing more than one gauge, you don't cut off the end of the wire after pressing it into the connector, but rather you just give yourself the appropriate amount of slack, run the wire to the next gauge, and continue. You do this for each of the three wires mentioned, thereby daisy-chaining them. This really cleans up some of the wiring mess that can be a hassle with other gauges. Each gauge still requires you to run its sensor harness wires from the sensor to the gauge's connector separately. Some sensors have only two wires while others have three. Pyrometers, temperature gauges, rail pressure, and HPOP gauges have a two-wire harness, while most other pressure gauges have a three-wire harness. All gauges obviously include the necessary sensors and wiring harness, with few exceptions. The harnesses are 10 feet in length with the exception of the Rear Differential Temp gauges, which come with a 20 foot harness. If needed, ISSPRO can build you a harness that's longer in length for applications that require it, at a nominal cost. The length of the supplied hook-up wire for the aforementioned power, ground, and lighting is also 10 feet.

One feature that's seldom touted is the style of connectors on most of the sensor harnesses. ISSPRO uses a weather-pack connector on their pyrometers and pressure gauges.  What's a weather-pack connector you ask? It's a special connector that has an internal silicone seal inside to prevent water ingress into the connector.

This is the same type of connector used on many of the connectors under your hood right now. The use of this style connector results in quicker installation time as well as the obvious benefit of moisture protection. Even their Rail Pressure and HPOP gauges have them. No need to cut and solder wires into your factory harness to gain access to the OEM signal for these gauges. You just unplug the factory connector, plug it into the ISSPRO harness, and plug in the other end of the harness back into your factory connector.

Wiring the EV Series

Wiring the EVs do take a little more effort, but it's certainly not anything that would prevent me from choosing these gauges. As stated earlier, some EV gauges that are electric include an amp box. This box has a 4-wire cable, 3-feet in length that simply plugs into the pigtail on the back of the gauge. I usually just mount the box somewhere under the dash and run the 4-wire cable up to the gauge. The amp boxes have 2 mounting holes if you wish to firmly secure them, but I opt for just using a couple of zip ties through the holes and attach them to a secure spot under the dash. Also exiting the amp box is a separate harness that connects to the sensor. This harness is also 3-feet in length. For Pyrometers this sensor harness will have ring terminals on its end. The ring terminals connect to another cable called a lead wire that has matching ring terminals that you connect to. The lead wire and sensor, called a thermocouple, aren't included with the pyrometers, but don't be alarmed; we kit our EV Pyrometers with lead wires and thermocouples to make ordering less confusing. The normal length lead wire we supply is 6 feet, but up to 50 feet can be had if it's required. Keep in mind here, a 6 foot lead wire, with the already 3 foot amp box harness, will net you an overall length of 9 feet from the amp box to the thermocouple (3 feet for the amp box harness and another 6 feet with the lead wire). Because the lead wires aren't included with the pyro gauge, we offer them with 2 connection styles for the thermocouple end, either ring terminal or the weather-pack connector end.

For other amp box gauges, like a Transmission Temperature gauges, the 3 foot sensor harness can easily be lengthened with additional 18 gauge wire. When purchasing a DieselManor gauge kit, we supply you with this additional wire because seldom is the 3 feet long enough.

The other connection that's needed for amp box gauges are power and ground. The power and ground wires for some gauges are already attached to the amp box, while others are not. Once again, we include this necessity when purchasing a DieselManor gauge kit. 

Lighting the EV series is the same no matter if it's an electric gauge with and amp box, or if it's a mechanical gauge with a tubing kit. All EVs have inch male spade terminals on their back. One terminal gets connected to ground and the other to your factory dimmer. There's no need to run separate lighting wires to each gauge if you have more than one.

Like the EV2 series, you can daisy-chain this part of the wiring, but the EVs don't come with any wiring for this. Once again, when purchasing one of our kits, we will supply you with an in-house, pre-wired harness for your lighting.  Something worth mentioning here dear reader, when I say "DieselManor gauge kit", I am talking about a complete gauge kit with the pillar and other installation accessories. If you purchase individual components, al-la-carte, you don't get these additional wiring items. If you're confused, as I think I am now, just give us a call and we'll explain it further.

For mechanical gauges, like Turbo Boost and Fuel Pressure, there's no wiring other then the lighting. These gauges usually require a tubing kit, and once again, we offer them in kit form to make ordering easier. The standard length for a tubing kit is 10 feet, but longer lengths are available.

Mechanical vs. Electric

One notable aspect of the EV2 series is that they're all electric. That means that their Turbo Boost and Fuel Pressure gauges have electric sensors instead of tubing kits that get plumbed to your pressure source. The nice thing about this is that there are no compression tube fittings that can develop a leak over time. While this is not an issue for mechanical Boost gauges, it can be a problem with mechanical Fuel Pressure gauges.  It's much easier, and more practical, to have an electric sensor for your Fuel Pressure gauge rather than running a gauge isolator, something that's required for mechanical Fuel Pressure gauges.  One drawback of using an electric Fuel Pressure gauge is that the sensors are delicate.  ISSPRO uses a heavy-duty electric sensor for all of the fuel pressure gauges, but occasionally the sensor could still fail.  This is because of the delicate nature of the inner workings of the sensors. When these sensors do fail, they manifest in gauge readings that are erroneous.  The needle on the gauge may start to jump up and down in a manner that is obviously inconsistent with what's actually going on in the fuel system.  Sometimes the gauges will just go to full sweep and stay there while powered up.  To combat this we recommend running a pressure gauge snubber.  We offer a pulsation-damping snubber that works so well that we haven't had any customers contact us with a sensor failure when using it.  This snubber simply gets inserted into your fuel source and the gauge sensor screws into the snubber.  Our snubber, part # FTG-SNB125-10, actually utilizes a small metallic filtering disk inside.  It provides accurate pressure readings to the sensor while preventing the "water-hammering" effect that is common in modern diesel fuel systems.

In the EV series their Boost gauges and Fuel Pressure gauges are mechanical.  As mentioned, for boost gauges this is not a problem, but it can be more of a nuisance when using a Fuel Pressure gauge.  The use of a mechanical gauge isolator is strongly recommended.  This isolator is different from a snubber entirely. The isolator actually prevents fuel from getting to the gauge by means of a bladder, or sometimes referred to as a diaphragm.  The isolator gets plumbed to your fuel system my means of a stainless steel braided fuel pressure hose.  The fuel enters the bottom of the isolator and pushes up against the internal bladder, in turn pressurizing the top half of the isolator which is plumbed to the gauge via a standard tubing kit.  Due to the internal air pocket in the top of the isolator, it's required to fill this void with antifreeze during the installation.

Optional Accessories and Upgrades

While there aren't any options for the EV line, other than the colored bulb covers for the black dial series, the same cannot be said for the EV2s. Probably the best feature of the EV2 series is that they all come standard with a warning lamp. The gauges all have a red LED located at the 6 O'clock position. This warning lamp does not come pre-set at the factory. It will only light up each time the gauges are powered up, signifying that the gauge is working. It will illuminate briefly then go out. The lamp can be programmed at any time with ISSPROs optional Attribute Software kit, part # R82003, at an additional cost. This PC based software can be used indefinitely and can program all EV2 gauges. It includes a CD-ROM and USB cable which is inserted into a special connector on the back of the gauge that's accessed by removing a protective tab on the gauge housing. This software is powerful and can do more than just program the warning lamps. It can also be used to adjust backlighting intensity, change the polling speed so the pointer moves slower, as well as program another optional accessory; their Output Driver Module, part # R82006. This module gets plugged into the back of the gauge and is programmed with the software to trip its internal relay, which in turn can be used either directly or indirectly with additional relays to turn on/off other accessories, such as a fan, pump, water-methanol injection; you name it.

Other accessories that can be purchased include extra sensors that can be wired in to switch between 2 different sensors.  This allows for having 1 gauge that can be toggled between 2 different temperature or pressure sensors, allowing for monitoring different input locations without the need for purchasing another gauge.

Selection Criteria

So, you're thinking of getting a set of gauges, are you?  Not sure on EV or EV2? Well, read on.

The EV series are no longer ISSPRO's emphasis for new types of gauges. That doesn't mean that they're being discontinued, but rather ISSPRO is focusing their attention on releasing newer and more options for their newer EV2 line. That may be a criteria for choosing which family of gauge you want if you think that you may want something that isn't available in the EV line. For example, if you want a Pyro, Turbo Boost, and Trans Temp gauges now, and want to add a Rail Pressure gauge at a later time. The Rail pressure gauge isn't available in the EV line, so in order to ensure that all of your gauges match, you probably want to go with the EV2's now, so that later you can buy a matching EV2 Rail Pressure gauge. I thought about listing in this article all of the different EV and EV2 gauges that are available, but honestly that would be too space consuming as well as confusing. Instead I've listed the most popular gauges that we sell. This composes about 90% of our gauge sales. If this list isn't detailed enough for you, you can always get in contact with us and we can help you further.

EV2 Series

  • Pyrometer, 1600F, 2000F in Color-Coded and Non-color Coded
  • Turbo Boost 30, 40, 60, 100, 120, 150PSI
  • Trans Tamp 0-240F, 100-280F, 140-320F
  • Ele. Fuel Pressure, 20, 30, 40, 60, 100, 150PSI
  • Rail Pressure (Dodge and GM)
  • HPOP Pressure (Ford)
  • Exhaust Gas Backpressure 40, 60, 100, 120, 150PSI
  • Coolant Tamp 0-240F, 100-280F, 140-320F
  • Engine Oil Temp 0-240F, 100-280F, 140-320F

EV Series

  • Pyrometer, 1500F, 1800F in Color-Coded and Non-color Coded
  • Turbo Boost 30, 40, 60, 100 PSI
  • Trans Tamp 100-280F, 140-320F
  • Mechanical Fuel Pressure, 30, 60, 100PSI
  • Coolant Tamp 100-280F, 140-320F
  • Engine Oil Temp 100-280F, 140-320F

Once again, this list is only a sample of their offerings. There are many more EV and EV2s available, like Speedometers, Tachometers (in 2-1/16" and 3-3/8"), Fuel Level gauges, Voltmeters, Ammeters, Nitrous Pressure, even PRI Reservoir gauges, whatever those are.

The following is a side-by-side comparison between the two lines, detailing some of the basic features and functionality.




Size: Diameter

Most 2-1/16", with some

Most 2-1/16", with some

Size: Depth for 2-1/16" gauges



Mounting Bracket



Sensor Connection

Standard (Weather Pack optional on Pyro)

Most Weather Pack

Lighting Type

Incandescent bulb

LED internal

Lighting Color

Changeable in Black Dial series only

Not changeable

Water Ingress Protection

Frontally sealed

Frontally sealed with optional rear sealing

Fog proof

yes, prior to assembly

yes on fully sealed version

Incl Sensors and wiring

most *

yes *


only for lighting

Power, Gnd, Lighting

Gauge Styles




12VDC (24VDC optional)

12VDC (24VDC optional)


Convex Glass

Flat Glass

Programmable Warning Lamp



Output driver module



Needle movement

Air-core or mechanical

Stepper motor

Temp Compensated Pyro



OEM Matched

some vehicles

Yes for most popular models

Amp Box

Included when required


Origin of Mfg.




1 year

1 year

* EV1 Pyrometers do not include thermocouple or lead wire but are included when purchasing from DieselManor.
EV1 and EV2 Fuel level gauges do not include sensors but are available. Consult sales associate with your signal type required.

Final Thoughts

To summarize, there are differences between the EV and EV2 gauges. Choosing which series to go with is something that's just a matter of preference on what criteria is most important to you.  They're both quality built gauge lines that look great and function well. If you interested in more information be sure to check out our YouTube page at  We're releasing more videos which will give you a better look at these gauges and offer some more detailed information such as installation procedures, wiring techniques, and answering the most common questions we receive regarding their use and features.



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