If you're currently staring at your engine bay or scrolling through diesel forums trying to decide on the he300vg vs he351ve, you're likely dealing with a 6.7L Cummins that needs some love. These are the two heavy hitters in the world of Holset Variable Geometry Turbos (VGT), and while they might look pretty similar to the untrained eye, they've got some distinct differences that can make or break your weekend install.
Choosing between these two isn't just about which one "sounds better" or which one you found a deal on at a local scrap yard. It's about compatibility, how you use your truck, and how much you enjoy (or hate) messing with electronics. Let's break down what actually sets these two apart and why it matters for your rig.
The Old Guard: Understanding the HE351VE
The HE351VE was the pioneer for the 6.7L Cummins, showing up around the 2007.5 model year and sticking around through 2012. It was a massive jump in technology at the time because it introduced the sliding nozzle VGT design. Instead of a traditional wastegate, it uses a sliding ring inside the exhaust housing to change the speed of the exhaust gases hitting the turbine wheel.
This is why your 4th gen Cummins sounds like a jet engine when it's cold or when you've got the exhaust brake engaged. The HE351VE is a workhorse, but it has a reputation. Because it's an early VGT design, it's pretty prone to soot buildup. If you spend a lot of time idling or putting around town without letting the truck stretch its legs, that sliding ring can get stuck. Once that happens, you're looking at a limp mode situation or a very expensive paperweight.
The actuator on the HE351VE is a bit of a monster, too. It's a bulky electronic unit that uses engine coolant to stay at a reasonable temperature. If you've ever had to swap one out, you know it's a messy, cramped job that usually results in some scraped knuckles and a lot of spilled antifreeze.
The Evolution: What Changed with the HE300VG?
When 2013 rolled around, Ram and Cummins decided to tweak the formula, and that's where the HE300VG comes into play. You'll find these on the 2013 to 2018 trucks (and some later versions). On the surface, it does the exact same thing as the 351, but the internals and the way it "thinks" are different.
The HE300VG is essentially a more refined version of the VGT platform. The biggest change most guys notice immediately is the actuator. It's smaller, more efficient, and it doesn't rely on the same heavy-duty coolant cooling path in the exact same way the older ones did (though it still gets plenty hot).
One of the internal improvements was the ball screw mechanism for the sliding nozzle. In the older HE351VE, the gear setup could sometimes be the weak point. The HE300VG tried to smooth that out to make the movement more precise. Does it still get clogged with soot? Absolutely. It's still a VGT, after all. But it's generally considered a bit more robust when it comes to the electronic communication side of things.
Side-by-Side: The Technical Nitty-Gritty
When you look at the he300vg vs he351ve from a performance standpoint, they are surprisingly close. Both usually sport a 60mm compressor wheel (give or take depending on the specific assembly number), which is plenty for a daily driver or a mild tow rig. They aren't "big" turbos by any stretch of the imagination, but they provide that instant spool-up that makes a 6.7L feel so torquey off the line.
The real headache comes when you try to swap one for the other. * The Flange: Both typically use a T4i (T4 international) flange, but the physical spacing and the orientation of the outlet can vary. * The Actuator Plug: This is the dealbreaker for most. The wiring harness on a 2010 truck is not going to plug directly into a 2014 turbo. The pinouts are different, and the communication protocol (how the truck's computer talks to the turbo) isn't a 1:1 match. * Coolant and Oil Lines: You'll likely find yourself bending lines or buying conversion kits if you're trying to put an HE300VG on an older truck.
Which One Spools Faster?
In a perfect world where both turbos are brand new and clean, the HE300VG usually has a slight edge in responsiveness. The refined electronics allow it to react just a hair faster to throttle input. However, if you're driving a 15-year-old truck with 200,000 miles on it, you probably won't notice the difference in spool time as much as you'll notice the difference in "is my turbo currently stuck?"
The HE351VE has a very "mechanical" feel to the exhaust brake. When it closes up, it hits hard. The HE300VG is a bit more progressive. Some guys prefer the aggressive bite of the 351, especially when they're hauling a 15,000-pound trailer down a mountain grade.
The Soot Problem: A Common Enemy
Regardless of which one you pick, both of these turbos hate one thing: carbon. Because they have moving parts inside the hot exhaust housing, they are naturally prone to seizing.
If you're comparing the two because your current turbo is dead, ask yourself how you drive. If you do a lot of short trips, neither of these is going to last forever. However, the HE300VG's slightly updated nozzle design seems to handle the heat cycles a bit better over the long haul.
A lot of guys in the diesel community actually recommend doing a "cleaning" service or using a turbo with a cleaning port, but honestly, once these things start to stick, the writing is usually on the wall. If you're choosing between the two for a replacement, go with the one that matches your truck's year unless you're prepared to dive deep into custom tuning and wiring adapters.
Why Swap? (The Conversion Struggle)
You might be wondering, "If the HE300VG is better, should I upgrade my older truck?"
Here's the honest truth: unless your HE351VE is toasted and you found an HE300VG for free, it's usually not worth the hassle of the conversion. You'd need a standalone controller or a very specific tuning setup to get the newer actuator to talk to the older ECM.
On the flip side, some guys actually go the other way. They'll "downgrade" to an older style or even a non-VGT fixed geometry turbo (like an S300) to get rid of the complexity altogether. But if you love your exhaust brake—and let's be real, that's the best part of owning a Cummins—you have to stick with one of these two.
Final Thoughts on Choosing Your Turbo
In the battle of he300vg vs he351ve, there isn't really a "loser." They are both highly capable turbos designed for a very specific job: making a 7,000-pound truck move like a sports car while being able to stop a massive trailer without using the wheel brakes.
If you have a 2007.5-2012 truck, stick with the HE351VE. It's what your truck knows, it's what the sensors expect, and it's a proven (if slightly soot-prone) design. If you have a 2013+ truck, the HE300VG is your bread and butter. It's a more modern, refined piece of equipment that handles the demands of newer emissions systems a little bit better.
At the end of the day, the best turbo is the one that stays clean and keeps your EGTs (Exhaust Gas Temperatures) in check. Whichever one you're running, do yourself a favor: take it out on the highway and let it eat every once in a while. Your VGT will thank you.