NOCO GB40 vs GOOLOO GT4000S: Which Jump Starter for a V8, Diesel, or Cold Start?
Updated 2026-08-24
Disclosure: As an Amazon Associate I earn from qualifying purchases. This comparison contains Amazon affiliate links.
The GOOLOO GT4000S is the better jump starter for big or diesel engines: its 4000A peak is rated to crank up to 12.0L gas / 10.0L diesel, versus the NOCO GB40's 1000A and a 6.0L gas / 3.0L diesel ceiling. Pick the NOCO GB40 for pocket-size portability and a lower everyday price on 4-cylinder, V6, and most gas V8 cars. Below is the spec-by-spec breakdown and an explicit "pick X if..." rule so you match the tool to your engine, not the marketing.
Specs Comparison
| Spec | NOCO Boost Plus GB40 1000A Jump Starter | GOOLOO GT4000S 4000A Jump Starter |
|---|---|---|
| peakAmps | 1000A peak | 4000A peak |
| gasEngineRating | Up to 6.0L gas | Up to 12.0L gas |
| dieselEngineRating | Up to 3.0L diesel | Up to 10.0L diesel |
| capacity | 24Wh lithium-ion | 20,000mAh |
| usbOutput | USB-A out (5V/2.1A) | 100W USB-C two-way + 150W DC out |
| size | Compact (~7.7 x 3.2 in) | Larger brick (~9.0 x 3.9 in) |
| display | LED status + 100lm light | 3.2" LCD + 400lm light |
Pros & Cons
NOCO Boost Plus GB40 1000A Jump Starter
Pros
- Genuinely pocket-size and light (~2.4 lb with clamps) — fits a glovebox or door pocket
- Lower street price; strong value for 4-cylinder, V6, and most gas V8 cars up to 6.0L
- UltraSafe spark-proof and reverse-polarity protection make it beginner-friendly
- NOCO has a wide US support and warranty network
Cons
- 1000A peak is marginal for large or cold diesels — rated only to 3.0L diesel
- Basic USB-A output (5V/2.1A) — recharges slowly and can't fast-charge a laptop
- No display screen; simple LED charge indicator only
GOOLOO GT4000S 4000A Jump Starter
Pros
- 4000A peak is rated to crank big gas V8s and diesels up to 12.0L gas / 10.0L diesel
- 20,000mAh with 100W two-way USB-C and 150W DC — doubles as a real laptop-capable power bank
- 3.2-inch LCD shows charge %, battery voltage, and jump status
- Recharges 0-100% in about 1.2 hours via the 100W input
Cons
- Bigger brick footprint — less glovebox-friendly than the GB40
- More cranking capability than a small-car or motorcycle owner needs
Our Verdict
For most drivers of gas cars — 4-cylinders, V6s, and gas V8s up to 6.0L — the NOCO GB40 is the smarter buy: 1000A is enough to crank those engines, it costs less, and it actually fits in a glovebox. Step up to the GOOLOO GT4000S if you run a large diesel, a heavy-duty truck, or you live where cold snaps sap cranking power — its 4000A peak (rated to 12.0L gas / 10.0L diesel) has the headroom a dead diesel needs on a frigid morning, and its 20,000mAh pack with 100W USB-C makes it a genuine power bank too. Simple rule: match the output to your biggest, coldest crank. If that's a normal gas car, the GB40 wins on price and portability. If it's a diesel or a truck, the GT4000S's raw output is the whole point.
Best for Budget
NOCO Boost Plus GB40 1000A Jump Starter
Best for Features
GOOLOO GT4000S 4000A Jump Starter
Buying Guide
- 1Peak amps vs engine size is the number that matters. Manufacturers rate jump starters both by peak amps and by the largest engine they'll crank. The GB40's 1000A peak is rated to 6.0L gasoline and 3.0L diesel; the GT4000S's 4000A peak is rated to 12.0L gasoline and 10.0L diesel. Peak amps are a brief surge, not sustained output, so treat the engine-liter rating as the real ceiling — it already accounts for how much surge current a starter motor of that size actually demands.
- 2Diesels and cold weather change the math. Diesel engines have higher compression and need far more cranking current than a gas engine of the same displacement, and cold temperatures cut a lead-acid battery's available current while thickening the oil the starter has to turn. That double penalty is why the GB40 caps out at 3.0L diesel while the same physical size class of gas engine goes to 6.0L. If you own a diesel pickup, a large SUV, or start engines below freezing, the GT4000S's 4000A headroom is not overkill — it's the margin that gets a stubborn engine to fire.
- 3Portability and everyday power-bank use favor different owners. The GB40 is the size of a large phone and weighs about 2.4 lb with its clamps, so it genuinely lives in a glovebox and is easy to hand to someone in a parking lot. The GT4000S is a larger brick, but that size buys a 20,000mAh battery, a 100W two-way USB-C port that can fast-charge a laptop, a 150W DC output, and a 3.2-inch LCD. If you want one device that jumps the car and charges your gear on a road trip, the GOOLOO is the multi-tool; if you only want an emergency starter, the NOCO's compactness wins.
- 4Price and who each is for. Both units typically sell around $100, but the GB40 is usually the cheaper, value pick and the GT4000S is priced for the extra capacity and output. Buy the GB40 if your biggest vehicle is a gas car up to 6.0L and you value pocketability and a trusted US brand. Buy the GT4000S if you need to crank a diesel or big truck, you face cold starts, or you want the jump starter to double as a serious portable power bank.
Honourable Mentions
Frequently Asked Questions
Is 1000A enough to jump-start a V8?
Can the NOCO GB40 start a diesel?
Is the GOOLOO GT4000S overkill for a normal car?
Which is better for cold-weather starts?
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. This comparison contains affiliate links. If you purchase via our links, KeenSift may earn a commission at no extra cost to you. This does not influence our rankings.