Best Diesel Additives of 2026

"I've been using this in my Ford F250, and the performance boost is obvious. My truck runs smoother, quieter, and more efficiently, and I can see a noticeable improvement in acceleration. The squeeze bottle is super convenient, making it simple to use with every fill-up. I highly recommend it for anyone wanting to keep their engine in top condition."

"After adding this to my 2016 Cummins, my fuel economy jumped from 15 to 19.5 mpg without any upgrades. The throttle feels livelier, shifting is easier, and I don’t fill up without it. Just be aware, the smell is strong—so if you store it in the cab, double-bag it!"

"I use this in all my diesel trucks. They keep running strong and haven’t had any issues, so maybe it's helping! I haven’t torn down my engines, but maybe that’s because I use this stuff regularly."

"I've tried various additives before, but with this kit, my engine is noticeably more responsive and fuel mileage has improved. I was surprised how quickly it started working—definitely impressed and will order again."

"After switching to this product, my Ford became much quieter, and my other vehicles are now running smoother with a 2-3 mpg boost. I don't know how it works, but it absolutely does. Highly recommend it!"

"As a Sprinter owner, I've always dealt with EGR issues every 15,000 km, but since using this additive, power loss and EGR sticking are things of the past. After 60,000+ km, my EGR only had a slight carbon film—maintenance is now so much easier."

"I've noticed significantly smoother engine operation and better mileage since using this fuel treatment. After a few tanks, my car's performance really improved, and it feels like a great investment for the price."

"Using this product in my vehicles for years has resulted in noticeable increases in fuel economy and a quieter engine. It works well for both gas and diesel, and the cost savings add up. Just be sure not to go over the recommended amount to avoid potential spark plug issues."

"I add this treatment to everything from my Corvette to my mower because it's an excellent upper cylinder lubricant and helps prevent fuel issues. While I use other products for cleaning and stabilization, Lucas stands out for lubrication, especially under heavy use or towing. I haven't had a single fuel-related problem since following this routine."

"I've been using this diesel treatment in my Ford F250 and I'm really impressed with the results. My truck runs smoother, fuel efficiency is up, and engine noise is down. The bottle is super convenient—just squeeze and pour, no mess. I love that it's easy to use with every fill-up and especially useful during cold weather. Definitely a must-have for keeping my truck in top shape."

"I tried this additive in both my diesel truck and farm tractor during a cold snap—temperatures dropped to 10 degrees, and both engines started right up without any gelling issues. I really think it's worth trying if you have a diesel vehicle and want reliable winter performance."

"I run the regular formula in the summer and switch to this one in the winter. I've noticed a real improvement in my fuel mileage and overall performance. It's hands down the best fuel additive I've used."

"After using this diesel treatment, I experienced noticeably smoother engine operation, quieter idling, and better throttle response almost immediately. The value is excellent since the two-pack covers up to 800 gallons. I feel confident knowing it helps keep injectors clean and protects the fuel system, making it a must-have for my regular maintenance."

"I had tried other additives before, but after about two months with this one, I saw real improvements in my Audi’s mileage and a clear return of power. My range increased, and I’m now seeing over 600 miles per tank. The product is easy to use and offers great results for the price—I'll keep using it from now on."

"I've been using this product for over a year, and I’ve been impressed by the boost in mileage and performance. As a mechanic with decades of experience, I’ve seen all sorts of additives, but this one actually works. I recommend it to my customers and friends."

"I drive an older Powerstroke and our winters often reach -30°F to -40°F. This additive has been a lifesaver for preventing fuel gelling—my truck starts smoothly, with less smoke on cold starts. I always switch to the winter formula by October and it has never let me down, no matter how harsh the weather gets."

"As a diesel truck owner, I use this for every fill-up. I've consistently gained 1-2 MPG and appreciate the added fuel system protection—that peace of mind is huge with expensive components at risk. In my opinion, every diesel in the U.S. should run an additive, and this one has proven its value time and again."

"Living up north with extremely cold temperatures, I rely on this product to keep my diesel flowing. While the bottle is tough to squeeze for me, I solved it with my own measuring method. The important thing is, the winter blend works reliably even when the weather turns nasty."

"I've tested Hot Shots Secret against several diesel anti-gel brands and this one outperforms all of them, especially in extreme cold. Knowing it protects down to -60F gives me peace of mind for the whole Midwest winter, and buying a gallon lasts me the season. Best value for the money."

"I use this in my 2019 Ford Super Duty in North Dakota, where it gets sustainably cold for weeks. With the right dosage, I've had zero gelling issues even with #2 fuel. The only thing I wish was easier is measuring the right amount from the gallon container, but a separate measuring cup solves that. Highly recommend for reliability."

"I have five diesel trucks and rely on this for all of them, including my construction equipment. The anti-gel formula works flawlessly in winter. My only minor complaint is that the packaging sometimes comes as two half-gallon jugs, which are easier to misplace, but the product itself has never let me down."

"I was seriously impressed after using this cleaner in my 1999 Volvo S70 GLT. After just a quarter tank, the check engine light disappeared and the car ran smoother, quieter, and with more power than ever before. I've tried other fixes, but this one actually worked. Highly recommended."

"My 2024 Ram HO Cummins had persistent lights for too frequent regens, and honestly, I was expecting a trip to the mechanic. After running half a tank with this treatment, the warnings cleared up, the DPF indicator reset, and I even noticed better fuel economy. This product made a real believer out of me. Will keep using it!"

"I drive a 2015 Duramax that started throwing codes and even went into limp mode. After using two tanks treated with this cleaner, the truck started smoothly, faults disappeared, and it now runs like new. I almost never write reviews, but this stuff exceeded all my expectations and completely cleared up my issues. If you're battling carbon buildup, look no further."

"I've been adding this to my 2025 Freightliner Cascadia and haven't run into any DEF problems since. I use half a bottle for my 25-gallon tank every few months, and it seems to keep things clean. There's some foaming when I fill up, but I think it's worth it for the long-term protection against corrosion and DEF issues."

"After using about 2 ounces, my DEF error codes cleared up in about three days. I’ve had good experiences with this brand on my diesel engines—their products really work."

"When my DEF quality light came on in my new 2025 Silverado 2500 Duramax, I added this product as recommended. After about 700 miles, the light hasn’t come back, so it seems to have refreshed my DEF fluid and solved the issue."

"We've been running this additive in our food truck throughout the Colorado winter, and it’s made a significant difference in preventing fuel gelling. The truck starts up way more easily during cold snaps when we use this."

"I switched to this additive on my son's advice—he’s a diesel mechanic—and I’ve found it’s much simpler to use than the Ford cetane additive. I use it every fill-up now and even noticed a slight boost in mileage compared to not using any cetane at all."

"After seeing strong recommendations online, I started using this in my 2016 Duramax to help keep the fuel system clean and lubricated. The jug is very convenient and doesn’t leak. I always use the higher dose and plan to use it in all my diesel equipment going forward."