Volvo 670 Vs 780 Weight?

Ask ten Volvo drivers how much heavier a 780 is than a 670, and you’ll get ten different answers — because the honest truth is the cab badge tells you far less about weight than your fuel tanks, sleeper length, and axle configuration do.

Table of Contents

TL;DR

Both 670 and 780 are cab-style codes in Volvo’s VNL naming system, not separate chassis
The 780 has a taller, longer high-rise sleeper; the 670 uses a shorter, lower cab
Real driver-reported tractor weights range from roughly 18,700 to 20,000 lbs for 780s and similar territory for 670s, depending on spec
Fuel tank size (120 to 300+ gallon combinations) swings total weight more than the cab code does
Rumors of a flat “2,000–3,000 lb” gap between the two are largely exaggerated once specs are matched

Volvo 670 vs 780 Weight: The Short Answer

The cab size difference is real, but it’s not the dominant factor in total tractor weight. The 780’s taller, longer sleeper adds some pounds over the 670, but fuel tank capacity, axle configuration, and options like extra chrome or a pusher axle typically move the needle far more than the badge alone.

I’ve pulled together real weigh-in numbers reported by working Volvo drivers to cut through the forum folklore around this exact question, since it comes up constantly among owner-operators cross-shopping these two cabs.

What 670 and 780 Actually Mean

Volvo’s VNL naming system uses a three-digit code for cab style, where 640/660/740/760/780 represent various full sleeper cabs with flat or high roofs. The “L” in VNL signals a long hood, distinguishing it from the medium-bonneted VNM and regional VNR.

In practice, the 780 is Volvo’s tallest, most spacious sleeper cab — the “condo” configuration many long-haul drivers favor for standing room — while the 670 is a shorter, lower-profile sleeper aimed at drivers who want a smaller footprint.

Pull quote: The 780 and 670 aren’t different trucks — they’re different sleeper boxes bolted onto the same basic Volvo platform.

What Real Drivers Actually Report

Reported weights vary far more by individual spec than by cab code alone. On TruckersReport’s Volvo forum, one owner-operator’s 2006 780 with full 240-gallon tanks and personal gear weighed in around 20,000 lbs, while a 2007 VNL780 with a D12 engine and half-full 120-gallon tanks came in lighter, at 18,700 lbs.

Meanwhile, 670 owners reported comparably wide ranges — one driver’s 2013 VNL 670 was described as “super light,” allowing 47,000 lbs in the box while staying legal with a half tank of fuel.

Quick Tip: If weight matters more to your operation than cab comfort, don’t assume the 670 automatically saves you meaningful payload — ask for the specific tractor’s actual scale ticket rather than trusting a rule of thumb about the badge.

Where the 780 Pulls Ahead

It leads on interior space and driver comfort, at some cost in cab weight. The taller high-rise sleeper gives standing headroom and more storage, which matters enormously for drivers spending weeks at a time in the cab.

Expert Insight: Drivers chasing maximum payload should scale their actual truck rather than trust cab-code folklore — the real spread between two similarly equipped 670s can be bigger than the average gap between a 670 and a 780.

Real-world scenario: An owner-operator comparing a 780 with dual 120-gallon tanks against a 670 with dual 150-gallon tanks may find the “smaller” 670 actually weighs more once fueled, simply because of tank capacity — not the cab.

Where the 670 Still Makes Sense

It leads on a lower overall footprint for drivers who don’t need the biggest sleeper available. Some drivers specifically choose the 670 for less bulk and reported fewer ride-comfort tradeoffs when properly specced with the right axle setup.

Pros and Cons by Buyer Type

The Maximum-Payload Owner-Operator

✅ Volvo 670: generally the lighter cab option when specs are matched apples-to-apples
❌ Volvo 780: taller sleeper adds cab weight that eats into legal payload margins

The Long-Haul Comfort-First Driver

✅ Volvo 780: taller, more spacious high-rise sleeper for weeks-long trips
❌ Volvo 670: smaller cab footprint means less living space on the road

The Buyer Cross-Shopping Used Trucks

✅ Either: real weight depends far more on fuel tank size and axle spec than cab badge
❌ Either: don’t trust listing descriptions alone — ask for an actual scale ticket

Alternatives Worth Considering

Choose a day-cab VNL if weight and cost matter most and you don’t need a sleeper at all — Volvo’s 300-series cab codes are built for regional routes without overnight stays.

Choose the VNL 860 with a D13 if you want maximum comfort and are open to newer engine options — some drivers report strong fuel mileage even at higher gross weights with turbo-compounded engines.

FAQ

How much heavier is a Volvo 780 than a 670? It varies significantly by individual spec, but real driver-reported figures put both cabs in a similar general range once fuel tank size and options are matched — the flat “2,000–3,000 lb” figure some drivers cite is often exaggerated.

Does fuel tank size affect weight more than the cab style? Often yes — tank combinations range from 120-gallon to 300-plus-gallon setups, and a full tank difference alone can outweigh the gap between cab styles.

What’s the actual difference between the 670 and 780 cabs? The 780 is Volvo’s tallest, most spacious high-rise sleeper, while the 670 is a shorter, lower-profile sleeper cab — both are part of the same VNL long-hood truck family.

Is a 670 always lighter than a 780? Not necessarily — individual spec differences like axle configuration, fuel tanks, and added equipment can make a heavily equipped 670 weigh close to, or even more than, a lightly equipped 780.

How can I find the actual weight of a specific used Volvo tractor? Ask the seller for a recent scale ticket or weigh the truck yourself — factory spec sheets and forum rules of thumb are far less reliable than an actual scale reading for that individual vehicle.

Key Takeaways

670 and 780 are cab-style codes within Volvo’s VNL lineup, not separate trucks
The 780’s taller sleeper adds some weight, but individual spec choices matter more
Fuel tank capacity swings total weight more dramatically than cab code alone
Real driver-reported weights for both cabs overlap significantly
Always verify actual weight with a scale ticket rather than relying on cab-badge assumptions

Next Step

Request a scale ticket for the specific tractor you’re considering rather than relying on general 670-vs-780 weight rules, since individual spec accounts for most of the variation.