Best Sat Nav for a 7.5-Tonne Lorry in the UK: What Actually Matters
The best sat nav for a 7.5-tonne lorry is the one that routes on your numbers: the height you measured with a tape, the weight on your plate, the length of your body. Any unit that lets you enter those and carries proper UK and European restriction data will keep you away from most of the trouble. The brand on the box matters less than whether it was set up right before the first job.
I'll go through what a 7.5-tonner actually needs, what to type in, and the things no sat nav can do for you. I run CMNAV on my own, I switch on and test every unit before it ships, and most of the questions below are ones I answer by email every week.
Why 7.5-tonners get caught out more than artics
A 7.5-tonne lorry sits in an awkward spot. It's tall enough to hit a railway bridge and long enough to get stuck in a village, but it's light enough that plenty of people drive one on a C1 entitlement without ever having done an HGV course. Removals, parcel runs, hire trucks for a house move, own-account deliveries. The driver is often thinking like a van driver, and the sat nav on the dashboard is usually a phone app that thinks it's guiding a car.
Network Rail recorded 1,666 bridge strikes between April 2024 and March 2025 – roughly one every five hours – and the most-struck bridge in Britain that year was on the A5 at Hinckley, hit 22 times. These aren't exotic roads. They're the roads a 7.5-tonner uses all day. Network Rail's own advice in its Wise Up, Size Up campaign starts with the same two things this article is about: know your height, and plan your route for it.
Good to know: a typical 7.5-tonne box body is around 3.5 metres tall and 8.3 metres long. A car is under 2 metres. A phone app doesn't know the difference unless it has a vehicle profile – and plain Google Maps and Apple Maps don't.
What to enter, and where the numbers come from
Don't take any of these from a brochure or a hire-desk leaflet. Take the height from a tape measure and the weights from the plate in the cab or door frame.
| Setting | What to enter | Where it comes from |
|---|---|---|
| Height | Your measured travelling height, rounded up to the next 10 cm. Include a roof-mounted air-con unit, beacon or anything else on top. | Tape measure, on level ground, unladen |
| Weight | 7,500 kg – the plated maximum, not what's on board today | The plate (manufacturer's or DVSA ministry plate) |
| Axle load / axle count | The maximum for the heaviest axle, and how many axles | Same plate |
| Length | Overall, bumper to tail-lift (or tail of the body) | Spec sheet, or measure it |
| Width | Body width (mirrors excluded) | Spec sheet |
| Trailer | Only if you tow one – then the combined length | Measure the outfit |
Why the plated weight and not the real one? Because UK weight-limit signs are about the maximum gross weight your vehicle is allowed to be, not what it weighs at that moment. An empty 7.5-tonner is still a 7.5-tonner as far as a "3T" sign is concerned. Enter the plated figure once and leave it alone.
Straight off the Starter Truck's screen. The vehicle profile lives in the settings, and it's the first thing to fill in – before the first postcode.
If you'd rather watch than read, the "editing vehicle dimensions" tutorial is linked in every order confirmation – it's here too. It takes about ninety seconds on the device.
The signs that actually catch a 7.5-tonner
Here's the bit most guides get wrong. A red-ring "7.5T" sign prohibits goods vehicles over 7.5 tonnes maximum gross weight, so a lorry plated at exactly 7,500 kg is normally fine to pass it (unless the sign says otherwise). What catches 7.5-tonners is the smaller stuff:
- 3T, 3.5T and 5T limits on weak bridges and village streets, often with "except for access" underneath
- Low bridges – anything signed under your travelling height, and a lot of them are between 3.0 m and 3.7 m
- Width limits of 6'6" (2.0 m) and 7'0" on country lanes, where a 2.5 m body simply doesn't go
A truck profile with the right weight and height set routes around all three. A car profile sees none of them.
Fast, Easy or Short?
My units offer three main routing methods. For a 7.5-tonner I recommend Easy as the default – it favours bigger, more suitable roads even if that adds a few minutes – with Fast as the alternative when you know the area. I don't recommend Short for anything larger than a car. Shortest distance across the Lincolnshire fens is a lovely way to meet a drainage ditch. You can also ask the unit for several route alternatives before you set off and pick the one you like the look of.
What a sat nav can't do for you
I'd rather tell you this before you buy than after:
- Road signs win. Always. If the sign and the screen disagree, the sign is right and the screen is a guide.
- Short local trips in rural or residential areas may still get an unsuitable suggestion, simply because the map has no better alternative to offer. On long runs the units are excellent at keeping you on the right roads; in the last mile, your eyes do the work. I say the same in my FAQ.
- "Except for access" is a judgement the sat nav can't make. If your delivery is inside the limit, you can use the road; the unit will still try to route you round it.
- Temporary restrictions – roadworks, a bridge closed last week – aren't in any map until the next update.
Important: if your lorry's travelling height is over 3 metres, the law requires the height to be displayed in the cab. Most 7.5-tonne boxes are. Check the notice is there and that it matches what you measured – hire fleets sometimes have the wrong body height on the sticker.
Which CMNAV unit for a 7.5-tonner?
All my truck models take the same vehicle profile and the same maps – UK plus 50 other European countries, Ireland included – so the choice is about the cab and how you work, not about safety.
Most chosen for 7.5 t
Starter Truck 7-inch
- Full vehicle profile, UK + 50 European countries
- Speed and red-light cameras, 7–8 character postcode search
- Driving-time and break management
- Truck POIs: KeyFuels and SnapAcc sites, lay-bys, truck parks, services
- Free lifetime map updates
Suits: same lorry, same sort of work, every day. The simple one.
See the Starter Truck
Starter Truck Plus 9-inch
- Same software and maps as the 7-inch
- Bigger screen for a wide cab
- Free lifetime map updates
Suits: wide cabs, or eyes like mine after a long shift.
See the 9-inch Starter
Traffic Truck 7 or 9-inch
- Android, Wi-Fi
- Live traffic over a hotspot from your phone
- Everything the Starter does
Suits: UK multi-drop work where a jam costs you a slot. I'm upfront that live traffic is patchy abroad.
See the Traffic Truck
360 Traffic Truck 7 or 9-inch
- Live traffic, Android, Wi-Fi
- Built-in Full HD dash cam
- Everything the Starter does
Suits: own-account drivers who want the footage for insurance.
See the 360 Traffic TruckTwo details that matter in a lorry and get missed on spec sheets: every unit ships with a 12–24 V cigarette-lighter charger, so it works in a 24 V cab without an adaptor, and the postcode search takes full 7–8 character UK postcodes, which is what you're given on a delivery sheet.
If you also drive a car or a van, you don't need a second unit. The sat navs work on vehicle profiles. Tell me before or after you order and I'll enable a car profile alongside the truck one before it ships; you put your own figures into each and select the right one before each journey. Routing always follows whichever profile is active.
Pro tip: start the engine first, then plug the charger in. Plugging in before you turn the key can blow the charger's internal fuse – that's the single most common "it won't charge" email I get, and it's avoidable. Full details under Power & audio in the FAQ.
Before your first job
Test it in familiar territory for a week – a couple of trips in the car will do. Watch what it does at a junction you know, check the height and weight you entered against the plate, and get used to where the route options live. I won't be much help when you're in a lay-by at 5 a.m. on day one; I can be a lot of help the week before. If something isn't right, you've got a 30-day money-back guarantee on new units to find out inside.
If you're new to lorries altogether, I've written about what to have in the cab on day one, and about why the cheap "truck" sat navs on Amazon aren't.
Truck sat navs tested before they ship
Every unit is switched on and checked by me before dispatch, with the latest available maps loaded. Have your height, plated weight and length ready for the profile screen – it's ninety seconds, and the tutorial is in your order confirmation.
Browse truck sat navsNot sure which one? WhatsApp me or email contact@cmnav.co.uk
Frequently asked questions
Does a 7.5-tonne lorry need a truck sat nav, or will a van one do?
It needs one with a vehicle profile – height, weight, length and width – and maps that carry restriction data. Whether the box says "truck" or "van" matters less than whether you can enter 3.5 m and 7,500 kg and have the routing respect it. A car sat nav or a plain phone app can't.
How tall is a 7.5-tonne lorry?
A typical 7.5-tonne box body is about 3.5 metres, but curtainsiders, refrigerated bodies and roof-mounted equipment vary. Measure yours with a tape on level ground and round up to the next 10 cm. If it's over 3 metres, the height must be displayed in the cab.
Will the sat nav avoid 7.5T weight-limit roads?
A "7.5T" sign prohibits goods vehicles over 7.5 tonnes maximum gross weight, so a lorry plated at exactly 7,500 kg normally isn't caught by it. The limits that do catch a 7.5-tonner are the 3T, 3.5T and 5T ones on weak bridges and village streets – and with the plated weight entered, the unit routes round those.
Do I enter the weight I'm carrying or the plated weight?
Plated. UK weight restrictions apply to the maximum gross weight on your plate, not the load on the day. An empty 7.5-tonner is treated as a 7.5-tonner.
Can I use a car sat nav or Google Maps in a 7.5-tonner?
Nothing stops you, but neither knows your height or weight, so they'll route you under a 3.4 m bridge or across a 3T limit without a flicker. Many drivers keep Google Maps running alongside a truck sat nav for live traffic – that combination works well. Google Maps on its own is the problem.
Does it work in a 24-volt cab?
Yes. The cigarette-lighter charger supplied with every unit is rated 12–24 V, so it plugs straight into a lorry socket. Start the engine before you plug it in.
Can I use the same unit in my car?
Yes. The units work on vehicle profiles. Let me know when you order and I'll enable a car profile alongside the truck one; you enter the figures for each and switch before every journey.