What size jump starter do you need? Peak amps and engine size compared
You want a portable jump starter for your own car or truck, and every box leads with a peak amp number from 1,000 to 3,000. Which size actually matches your engine, and why does a bigger amp figure not settle it? This page compares seven current models by the engine sizes their makers state.
What we compared and why
- The maker's stated engine range for your fuel type. Makers state the largest gas and diesel engines each model is rated for. That rating is the figure to match against your engine; the diesel rating is the smaller of the two for every model here that states both, so diesel owners read the diesel column.
- Peak amps, read within one brand. Peak amps are shown because every listing leads with them, but there is no single industry definition behind them. We use them only to compare models from the same maker.
- Air compressor or inflator. Some units add a tire inflator. Useful if you do not already carry one; it makes the unit larger.
- Headroom over your engine. We treat a model whose stated range covers your engine with room to spare as the fit, and one whose range ends exactly at your engine size as the minimum.
The models compared
| Model | Peak amps stated | Gas engines up to | Diesel engines up to | Air compressor named |
|---|---|---|---|---|
| NOCO Boost GB40 jump starter | 1,000 A | 6.0 L | 3.0 L | Not stated in listing |
| NOCO Boost GB50 jump starter | 1,500 A | 7.0 L | 4.5 L | Not stated in listing |
| NOCO Boost GB70 jump starter | 2,000 A | 8.0 L | 6.0 L | Not stated in listing |
| GOOLOO A3 jump starter with air compressor | 3,000 A | 9.0 L | 6.5 L | Yes |
| Clore Jump-N-Carry 12 V jump starter (JNC660) | 1,700 A | Not stated in listing | Not stated in listing | Not stated in listing |
| DEWALT jump starter with air inflator (DXAEJ14) | 1,600 A | Not stated in listing | Not stated in listing | Yes |
| TOPDON jump starter (JS3000) | 3,000 A | 9.0 L | 7.0 L | Not stated in listing |
Table values are read from each product's current Amazon listing at the time of this page's build and normalised to one unit by us. "Not stated in listing" means the listing does not give the figure; "Listing gives two values" means the listing states it two different ways, so we show neither.
We earn a commission if you buy through the Amazon links on this page, at no extra cost to you. Commissions never decide which products are listed or how they are described.
NOCO Boost GB40 jump starter
Who it fits: Gas cars and small SUVs, and small diesels up to the 3.0 L its listing states.
Skip it if: Your diesel is larger than 3.0 L; the GB50 or GB70 in this table state larger diesel ranges.
NOCO Boost GB50 jump starter
Who it fits: Mid-size diesels up to the 4.5 L stated, a step above the GB40 in NOCO's own range.
Skip it if: Your diesel is above 4.5 L; look at the GB70 or the 3,000 A models.
NOCO Boost GB70 jump starter
Who it fits: Diesel pickups and vans up to the 6.0 L stated, within NOCO's own range.
Skip it if: Your engine sits well inside the GB40's or GB50's stated range; the larger unit adds size you do not need.
GOOLOO A3 jump starter with air compressor
Who it fits: Diesel engines up to the 6.5 L stated, plus a built-in tire inflator in one unit.
Skip it if: You already carry a tire inflator and want a smaller unit; a jump starter without one is more compact.
Clore Jump-N-Carry 12 V jump starter (JNC660)
Who it fits: You want a maker that also states a cranking amp figure (425 A, per Clore) rather than peak amps alone.
Skip it if: You want an engine size printed for the model: Clore's product page does not give one, and its listing table shows none.
DEWALT jump starter with air inflator (DXAEJ14)
Who it fits: You want a jump starter and an air inflator in one unit and a stated peak amp figure in the middle of this table.
Skip it if: You need a stated engine size to match: the listing table shows none for this model.
TOPDON jump starter (JS3000)
Who it fits: Large gas and diesel engines: it states the largest ranges in this table, 9 L gas and 7 L diesel.
Skip it if: You drive a small car; a smaller unit in this table states enough range and is easier to store.
Match the engine, not the amp figure
Every jump starter box leads with peak amps, and the numbers in this table run from 1,000 A to 3,000 A. It is tempting to buy the biggest number. The figure that answers "will it start my engine?" is a different one: the largest engine size the maker states for each model, given separately for gas and diesel. This page puts those stated ranges side by side. It is research-based, from the current listings and the makers' own pages; we have not jump-started a vehicle with any of these units.
Find your engine size
Your engine's displacement, in liters, is in the owner's manual, on the vehicle maker's spec sheet for your trim, and often on the engine cover or the emissions label under the hood. Note the fuel too: every model in this table that states both figures gives a smaller diesel range than gas range, so read the column for your fuel.
Which models' stated ranges cover your engine
Here is which models' stated diesel range in the table reaches a given engine size (the Clore and DEWALT units state neither engine figure, so they are left out):
| Your diesel engine | Models whose stated diesel range reaches it |
|---|---|
| Up to 3.0 L | NOCO GB40, GB50, GB70, GOOLOO A3, TOPDON JS3000 |
| 3.1 to 4.5 L | NOCO GB50, GB70, GOOLOO A3, TOPDON JS3000 |
| 4.6 to 6.0 L | NOCO GB70, GOOLOO A3, TOPDON JS3000 |
| 6.1 to 6.5 L | GOOLOO A3, TOPDON JS3000 |
| 6.6 to 7.0 L | TOPDON JS3000 |
| Over 7.0 L | None of the stated ranges here |
For a gas engine, use the gas column the same way wherever the listing states it.
We treat a model whose range ends exactly at your engine size as the minimum, not the comfortable fit. If your engine sits at the top of one model's range, the next model up gives you headroom.
Why peak amps from different makers do not line up
Clore Automotive, which makes the Jump-N-Carry, writes that "peak amps" has no single meaning, while a cranking amp is an industry-defined (BCI) rating that means the same thing to everyone. Clore itself lists its JNC660 at 1,700 peak amps and 425 cranking amps. So a 2,000 A unit from one maker and a 3,000 A unit from another are not ranked by those numbers: the two makers may not measure the same thing.
That is why the table shows peak amps but this page does not use them to place models against engine sizes. Within one maker's range, the figure is still useful: NOCO's GB40, GB50 and GB70 step up in peak amps as their stated diesel ranges step up from 3.0 L to 4.5 L to 6.0 L.
Air compressor or not
The GOOLOO A3 and the DEWALT DXAEJ14 name an air compressor or inflator. If you do not already keep a tire inflator in the car, one unit covering both jobs saves space in the trunk. If you do, a jump starter without one is the more compact choice.
Which one if...
- Small or mid-size gas car: any model whose stated gas range covers your engine with some headroom; there is no need to go to the top of this table.
- Diesel pickup or van: start at the diesel table above and pick a model with headroom over your engine.
- You want a cranking amp figure, not just peak amps: the Clore JNC660, whose maker states 425 cranking amps.
- You also want a tire inflator: the GOOLOO A3 or the DEWALT DXAEJ14.
What this page does not tell you
We do not measure starting power, cold-weather performance or how many starts a charge gives, and we do not rank these units. Engine ratings are each maker's own. Before you connect any jump starter, read and follow the maker's instructions for clamp order and connection points on your vehicle, and your vehicle maker's instructions for jump starting.