NOCO GB40 vs GB70: Which Jump Starter Do You Need?
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Pick the NOCO GB40 if you drive a 4-cylinder or V6 car, crossover or small SUV: it covers gas engines up to 6.0L and fits in a glove box. Pick the NOCO GB70 if you drive a V8 truck, a full-size SUV or a diesel up to 6.0L, or if one pack has to cover every vehicle in the family. Both have the same spark-proof, reverse-polarity clamps, so the choice comes down to engine size and space.
The GB40 and GB70 are NOCO’s two best-selling classic Boost packs, and they look like the same product in two sizes. In a way they are, but the size difference changes who each one is for. The GB70 has twice the peak current, double the rated starts and a much brighter light, while the GB40 is half the weight and fits places the GB70 does not. This comparison goes through each difference and ends with a simple pick by vehicle.
NOCO GB40 vs GB70: Side-by-Side Specs
| Spec | NOCO GB40 | NOCO GB70 |
|---|---|---|
| Peak current | 1000A | 2000A |
| Gas engines | Up to 6.0L | Up to 8.0L |
| Diesel engines | Up to 3.0L | Up to 6.0L |
| Starts per charge | Up to 20 | Up to 40 |
| Recharge time | About 3 hours | About 6 hours |
| Flashlight | 100 lumens | 400 lumens |
| Weight | About 2.5 lb | About 5 lb |
| Housing | IP65 | IP65 |
| Clamp safety | Spark-proof, reverse-polarity | Spark-proof, reverse-polarity |
NOCO Boost GB40 1000A Jump Starter
Gas up to 6.0L, diesel up to 3.0L
Check Price on AmazonNOCO Boost GB70 2000A Jump Starter
Gas up to 8.0L, diesel up to 6.0L
Check Price on AmazonEngine Coverage: The Difference That Matters Most
This is the deciding factor. The GB40 is rated for gas engines up to 6.0L and diesels up to 3.0L. The GB70 doubles the diesel rating to 6.0L and raises gas to 8.0L.
In everyday terms, the GB40 covers almost every four-cylinder and V6 car, crossover and minivan. The GB70 adds V8 pickups and SUVs (5.3L, 5.7L, 6.2L and similar), vans, inboard boats and light-duty diesels like the 3.0L Duramax and EcoDiesel. Cold weather pushes the decision further toward the bigger pack, because a cold engine needs more current to turn over. If your engine is near the GB40’s limit and you live somewhere with real winters, the GB70 is the safer choice.
Winner: GB70, by a wide margin, if you have a large engine. A tie if you only drive small cars.
Size and Weight
At about 2.5 lb, the GB40 fits a glove box, a seat-back pocket or a motorcycle saddlebag. The GB70 weighs about 5 lb and is too big for most glove boxes; it goes under a seat, in a center console on many trucks, or in the trunk. That sounds minor, but a jump pack that is easy to keep in the car is the one that is there when you need it.
Winner: GB40.
Starts per Charge and Repeat Attempts
NOCO rates the GB40 for up to 20 starts per charge and the GB70 for up to 40. Real-world numbers depend on engine size, temperature and how long you crank, but the GB70’s bigger battery gives more margin to try again after a failed start or to help a second vehicle.
Winner: GB70.
Charging Time
The GB40 recharges in about three hours, the GB70 in about six. Neither uses the USB-C Power Delivery found on NOCO’s newer Boost X models, so if quick top-ups matter more than size, look at our GB40 vs GBX45 comparison.
Winner: GB40.
Flashlight and Power Bank
The GB70’s 400-lumen LED is four times brighter than the GB40’s 100 lumens and makes a real difference at night under a hood. Both have a USB output for phones and tablets; neither charges a laptop.
Winner: GB70.
Safety and Build
Here they are identical. Both use NOCO’s UltraSafe clamps with spark-proof and reverse-polarity protection, both have a manual override for batteries too flat to detect, and both have IP65 housings with rubber over-molding. Either one is safe for a modern car with sensitive electronics, including the modules that handle keyless entry and the immobilizer.
Winner: Tie.
Which One Should You Buy? Pick by Vehicle
| Your vehicle | Pick | Why |
|---|---|---|
| Compact car, sedan, hatchback | GB40 | Plenty of rating, fits the glove box |
| Crossover or small SUV (4-cyl or V6) | GB40 | Covered by the 6.0L gas rating |
| Minivan | GB40 | V6 engines are within its rating |
| V8 pickup or full-size SUV | GB70 | 8.0L gas rating gives cold-weather margin |
| 3.0L diesel truck or SUV | GB70 | GB40 is right at its 3.0L diesel limit |
| 6.6L or 6.7L heavy-duty diesel | Neither | Choose a pack rated for 7.0L diesel or more |
| Household with car and truck | GB70 | Covers both vehicles |
| Motorcycle, ATV, lawn tractor | GB40 | Small and light enough to carry |
For heavy-duty diesels, our guide to the best jump starters for diesel trucks compares packs rated for 7.0L and 8.0L engines.
Three Real-World Scenarios
A commuter with a compact SUV
A 2.0L turbo crossover, parked outside, occasional cold mornings. The GB40 covers it with margin, fits in the glove box and recharges in about three hours. The GB70 would work too, but it would live in the trunk and add weight for no real benefit.
A family with a sedan and a half-ton V8 pickup
One pack has to handle both. The GB70 is the clear choice: its 8.0L gas rating covers the V8 in winter, and it starts the sedan easily. Keep it in whichever vehicle is driven more, or in the truck, since that is the one the GB40 cannot reliably help.
A rider with a motorcycle and a small car
The GB40’s small size and short cables suit a motorcycle well, and it covers the car. The GB70’s bigger clamps can be awkward on small motorcycle terminals.
Caring for Either Pack
Both are lithium packs, and the same habits keep them ready. Recharge after every use and every two to three months in storage. Avoid leaving them in direct sun on a hot dashboard. In deep cold, bring the pack inside before a morning you expect to need it. Check the clamps and cable for damage once in a while, and keep the jaws clean so they grip properly. With that routine, either pack should be ready for years.
The Verdict
The GB40 is the better buy for most car owners: it is smaller, recharges faster and covers the engines most people drive. The GB70 is the better buy for truck and large SUV owners, light diesel owners, and anyone who wants one pack for the whole household. If you are unsure and you have the space, choose the GB70. A pack with spare capacity works on a small engine, but a small pack cannot stretch to a big one.
For more detail on each model, read our full NOCO GB40 review and NOCO GB70 review.
Related Guides
- 7 best portable jump starters for cars, trucks and SUVs
- NOCO Boost GB40 review
- NOCO Boost GB70 review
- How to jump start a car safely
FAQ
Is the GB70 worth it over the GB40?
Only if you need its larger rating. For cars and small SUVs, the GB40 does the same job in a smaller package. For V8 trucks and diesels up to 6.0L, the GB70 is worth it.
Can the GB40 start a V8 truck?
It is rated for gas engines up to 6.0L, so it may start a smaller V8 on a warm day, but it has little margin. The GB70 is the reliable choice for V8 trucks, especially in cold weather.
Do the GB40 and GB70 use the same clamps?
Both use NOCO’s spark-proof, reverse-polarity clamps. The GB70’s cables and clamps are larger to handle its higher current.
Which holds its charge longer in storage?
Both lithium packs hold a charge for months. The GB70 starts with a larger battery, but the right habit for either is to recharge after use and every two to three months.
Is there a NOCO pack between the two with USB-C?
Yes, the GBX45 is rated for 6.5L gas and 4.0L diesel and recharges in about 48 minutes over USB-C. See GB40 vs GBX45.