Garmin dezl 780 LMT-S, GPS Truck Navigator, 7" Display

Quick take

The Garmin dezl 780 LMT-S is a 7-inch trucking GPS designed to handle big-vehicle navigation with custom truck routing and driver alerts for common risk points like low bridges and sharp turns. It’s built for everyday cab use with voice navigation, Bluetooth hands-free calling, and built-in Wi‑Fi for updates. Biggest potential drawback: a meaningful subset of buyers report software glitches and Smart Link app connectivity issues, so you’ll want to be prepared to troubleshoot setup if you plan to rely heavily on the phone app.

Pros and cons

Pros

  • 7-inch screen is easier to view and touch than smaller trucking GPS units.
  • Truck-specific routing features, including alerts tied to vehicle size, load, and weight.
  • Voice control plus Bluetooth hands-free calling and smart notifications via the Smartphone Link app.
  • Built-in Wi‑Fi for map and software updates without using a computer.

Cons

  • Some buyers report software performance problems and navigation/search quirks.
  • Smartphone Link app connectivity may be unreliable for certain setups.
  • Battery life is rated around 2 hours, so it may not suit extended unplugged use.

What buyers think

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Buyer-review evidence points to two consistent themes. First, drivers who like the device typically cite the large display, smooth usability, and accurate enough mapping and routing for their needs, especially when the truck profile is set up for dimensions and weight. Second, there is enough feedback about software and app behavior (including search frustrations and Smart Link not behaving as expected) that buyer confidence can vary by use case and setup.

Overall, the review signal is stronger for drivers who want truck-focused routing with a big screen, and weaker for drivers who depend on flawless smartphone-app integration.

Design and display: built for reading fast while driving

The standout hardware feature is the 7-inch touchscreen (6.95 inches reported as a screen size). Multiple reviews emphasize that the larger screen improves readability and makes touch interactions easier while navigating, including when you want to keep trip-related info visible alongside the main map.

Truck routing features and route confidence

Dez'l routing is the core reason shoppers look at this class of unit. The device supports custom truck routing based on your truck size, load, and weight, and it includes alerts for common hazards such as upcoming bridge height issues, sharp curves, and steep grades.

It also includes an “Easy Break Planning” approach with timely notifications and a Truck & Trailer Services directory that you can search by brand or amenities (for example, places that offer specific services like showers). This can help you plan stops without leaving the navigation flow.

Connectivity and updates in the cab

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This model targets modern connectivity without making you tether everything to a computer. It includes built-in Wi‑Fi for map and software updates. It also supports live services (like traffic and weather) when you use the free Smartphone Link app on a compatible smartphone.

For in-cab distraction control, it offers voice control and Bluetooth hands-free calling, and it uses smart notifications (via Smartphone Link).

Important buyer-fit note: Some reviews describe Smartphone Link not connecting or behaving unexpectedly, so it may be wise to treat phone integration as “useful when it works,” not as the only path to getting good navigation.

Mounting and installation reality

The kit includes a powered magnetic mount for secure attachment and easier removal when you exit the cab. Reviews also suggest that some drivers may prefer alternative mounting solutions depending on their vehicle (for example, using a different mount style if windshield placement isn’t practical).

Battery and daily power expectations

Battery life is listed at an average of about 2 hours. In practice, that means many drivers should plan to keep the unit powered while working, using the battery mainly as a short buffer rather than for extended off-cable navigation.

Pros and cons recap

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  • Buy it if: You want a truck GPS with a large screen, truck-specific routing, and practical alerts for vehicle constraints, and you value voice control plus easy update options (Wi‑Fi).
  • Consider something else if: You need phone-app integration to be completely seamless for your workflow, and you’re not interested in troubleshooting Smartphone Link behavior.
  • Best for: OTR or regional drivers who frequently navigate with varying trailer or load setups and benefit from a bigger display in motion.
  • Less ideal for: Shoppers who plan to rely primarily on unplugged battery use for long stretches.

Verdict

The Garmin dezl 780 LMT-S is a strong fit for drivers shopping specifically for a trucking GPS that prioritizes truck-aware routing and driver alerts, backed by a readable 7-inch touchscreen. If you like the idea of voice navigation and in-cab connectivity, it aligns well. Just be aware that software and Smartphone Link app integration have enough negative reports to influence the buying decision, especially if your workflow depends on a phone-app connection working exactly right.

FAQ

Is the Garmin dezl 780 LMT-S good for truck routing and vehicle size constraints?

Yes. It supports custom truck routing based on your truck size, load, and weight, and it includes alerts for items like bridge height issues, sharp curves, and steep grades. That truck-aware approach is the main reason it’s positioned for trucking use.

Does the Garmin dezl 780 LMT-S use Wi‑Fi for updates?

Yes. It includes built-in Wi‑Fi for map and software updates without needing a computer.

How does Smartphone Link affect live traffic and weather?

The device can provide live services such as traffic and weather when you download and use the free Smartphone Link app on a compatible smartphone.

What is the battery life on the Garmin dezl 780 LMT-S?

The listed battery average life is about 2 hours, so it’s best thought of as a limited backup rather than a long unplugged-navigation solution.

Is it a good choice if I want voice control and hands-free calling?

It supports voice-activated navigation and Bluetooth hands-free calling, plus smart notifications when used with Smartphone Link.

Will I need a separate mount for my truck?

The package includes a powered magnetic mount, which works for many vehicles. However, some drivers may prefer alternative mounting depending on where they can place the unit so it stays within their preferred viewing range.

Can it work with Garmin eLog for ELD and Hours of Service recording?

It is compatible with Garmin eLog compliant ELD setups, which are sold separately. The goal is subscription-free HOS recording without requiring a smartphone or tablet.

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Specifications

Product TitleGarmin dezl 780 LMT-S, GPS Truck Navigator, 7" Display
CategoryElectronics > GPS, Finders & Accessories > Trucking GPS
BrandGarmin
ManufacturerGarmin
Model Name010-01855-00
Model Number010-01855-00
Compatible with Vehicle TypeTruck
Screen Size6.95 Inches
Additional FeaturesTruck and Trailer Services Directory; Custom Truck Routing, Road Warnings; Service History Log, Voice-Activated Navigation; Lifetime Map and Traffic Updates
Connectivity TechnologyWi-Fi
Map TypesCity Tour, Street
Audio Output ModeStereo
Battery Average Life2 Hours
Mounting TypeDashboard Mount, found in image
Resolution1024 x 600
Operating SystemWindows
Touch Screen TypeCapacitive
Display Type6.95" super wide view IPS, color TFT, with on-cell capacitive touch panel
Human-Interface InputTouchscreen
Compatible DevicesSmartphone
Control MethodTouch, Voice
Are Batteries IncludedYes
Supported Satellite Navigation SystemGPS
Connectivity ProtocolWi-Fi
Built-In MediaLifetime maps and live traffic, Preloaded City Navigator for North America, USB Cable, Vehicle suction cup mount with powered magnetic mount, and Quick Start Manual, dezl 780
UPC753759207779
Global Trade Identification Number00753759207779

Available variants

Style

  • Truck Navigator
  • With Built-in dash cam

Pattern

  • GPS Truck Navigator

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