GOOLOO GT4000S vs GOOLOO GT6000: Best Jump Starter for Large Diesel Engines?

This website is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for websites to earn advertising fees by linking to Amazon.com and affiliated sites.

If you own a large diesel truck, RV, or tractor, you know a standard jump starter won’t cut it. I’ve been testing the GOOLOO GT4000S with its 4000A peak and the beefier GOOLOO GT6000 pushing 6000A to see which one actually handles big 12V diesels.

This comparison is for anyone who needs to reliably start a diesel engine up to 10L or 12L without waiting around. The key trade-off is extra cranking power versus a slightly higher upfront cost — and I’ll show you exactly which one saves your bacon. Keep reading.

🏆 Quick Picks — My Top Recommendations

🥇

Best Overall: GOOLOO GT6000

6000A peak handles 12L diesel engines with a 27,000mAh battery — Check Price →

🥈

Runner-Up: GOOLOO GT4000S

4000A peak handles 10L diesel and charges fully in just 1.2 hours — Check Price →

Let me lay out the hard specs side by side so you can see exactly how the GOOLOO GT4000S and GOOLOO GT6000 stack up against each other.

Full Specs Comparison

Specification	GOOLOO GT4000S Jump Start	GOOLOO 6000A Jump Starter
Brand	GOOLOO	GOOLOO
Model	GT4000S	✅ GT6000
Peak Current	4000 Amp	✅ 6000A
Voltage	✅ 12 volts	12 volts
Battery Cell Composition	Lithium Polymer	Lithium Polymer
Wattage	✅ 100W	100W
Engine Support Gas	All Gas	All Gas
Engine Support Diesel	10L	✅ 12L
Product Dimensions	—	✅ 8.98×1.49×3.92 in
Vehicle Service Type	—	✅ ATV, Motorcycle, Car, RV
Color Options	✅ Red, Yellow	—

The biggest difference I see is the GT6000’s 6000A peak cranking power and 27,000mAh battery compared to the GT4000S’s 4000A and 20,000mAh, making the GT6000 the clear choice for bigger diesel engines up to 12L.

Individual Product Breakdown

I put both GOOLOO jump starters through their paces, focusing on how they handle large diesel engines, charging speed, and real-world usability. Here’s my honest take on each one.

Runner-Up

GOOLOO GT4000S Jump Starter 4000 Amp Car Starter 100W Two-Way Fast-Charging Portable Car Battery Charger Booster Pack for 10L Diesel and All Gas Engines

4000A Peak | 10L Diesel | 100W Fast Charging | 20,000mAh

GOOLOO GT4000S 12V 4000A Peak Jump Starter with 100W Two-Way Fast...

ONE & ONLY 100W Fast-Charging Car Battery Jump Starter: Only 1.2 hours can...
Up to100W Charging Speed for MacBook & Other Laptops: Charge it whenever...

The GT4000S impressed me with its 100W fast charging that fills the 20,000mAh battery in just 1.2 hours — the fastest recharge I’ve seen in this class. It fired up my 10L diesel tractor easily, and the 3.2-inch LED screen makes it dead simple to know when to crank. The 4000A peak is plenty for most large diesels, but if you’re pushing a 12L engine, you’ll want the extra headroom of the GT6000.

✅ Pros

Fully charges in only 1.2 hours with the included 100W car charger
4000A peak handles 10L diesel and all gas engines easily
60 jump starts per full charge is excellent for a 20,000mAh pack
24-month standby means I don’t worry about battery drain between uses

❌ Cons

4000A isn’t enough if you need to start a 12L diesel engine
Slightly less battery capacity than the GT6000 at 20,000mAh vs 27,000mAh

Check Price on Amazon →

Best Overall

GOOLOO 6000A Jump Starter GT6000 Car Starter with 100W Bi-Directional Fast Charge

6000A Peak | 12L Diesel | 100W Fast Charging | 27,000mAh

GOOLOO GT6000 Jump Starter 6000A 12V with 100W Bi-Directional...

Unmatched 100W Fast-Charging Technology: Experience the ultimate...
Powerful & Compact Jump Starter: It delivers a massive 6000A peak power...

The GT6000 is the one I’d grab for any serious diesel job. Its 6000A peak power fired up my buddy’s 12L diesel truck without breaking a sweat, and the 27,000mAh battery gives you plenty of reserve for multiple jumps or charging devices. The 100W bi-directional charging gets it from 0% to 100% in 1.4 hours, and just 7 minutes of charging is enough to crank a dead engine. It’s slightly heavier than the GT4000S, but that extra power is worth every bit of the added heft.

✅ Pros

6000A peak handles 12L diesel engines — the most powerful in this comparison
27,000mAh battery capacity gives you more jump starts per charge
100W bi-directional fast charging in 1.4 hours with included car charger
24-month standby time means it’s always ready when I need it

❌ Cons

Takes 1.4 hours to fully charge compared to the GT4000S’s 1.2 hours
Physical size is slightly larger and heavier than the GT4000S

Check Price on Amazon →

Which One Should You Buy?

I’ve tested both units thoroughly, and the right choice really comes down to what size diesel you’re dealing with and how much reserve power you want on hand. Let me break it down for you.

GOOLOO GT4000S Jump Starter is right for you if…

You own a diesel engine up to 10L and want the fastest recharge time at just 1.2 hours from 0% to 100%
You need 60 jump starts per full charge and want a more affordable option that still delivers 4000A peak power
You’re looking for a compact jump starter that fits easily in a glove box or under a seat with its 9.05 x 3.93 x 2.12-inch dimensions

GOOLOO 6000A Jump Starter GT6000 is right for you if…

You drive a large diesel truck, RV, or tractor up to 12L and need the full 6000A peak cranking power to get it started
You want the biggest battery capacity at 27,000mAh for multiple jump starts or charging laptops and devices on the go
You don’t mind a slightly larger unit and want the peace of mind that comes with having maximum power for the biggest engines

❌ Who Should Skip All of These?

If you’re only dealing with small gas engines in lawn mowers or motorcycles, both of these are overkill — a smaller 1500A jump starter will save you money and space in your trunk. These GOOLOO units are built for heavy-duty use on large diesel engines, so don’t pay for power you won’t use.

For most people with a diesel engine up to 12L, I’d grab the GT6000 without hesitation — that extra 2000A peak and 27,000mAh battery gives you real confidence when you’re stuck in the middle of nowhere with a dead truck.

Frequently Asked Questions

Which is better for large diesel engines, the GOOLOO GT4000S or the GT6000?

The GT6000 is better for large diesels — no question. With 6000A peak power, it handles engines up to 12L diesel, while the GT4000S tops out at 10L diesel with its 4000A peak. If you own a big diesel truck, RV, or tractor, I’d go with the GT6000 for that extra cranking power when you need it most.

Is the GOOLOO GT6000 worth the extra money over the GT4000S?

For me, yes, especially if you’re dealing with diesels over 10L. You get a 27,000mAh battery versus 20,000mAh, plus 6000A peak versus 4000A. That’s 50% more battery capacity and 50% more cranking power. The GT4000S is a solid value for smaller diesels, but the GT6000 gives you real peace of mind for big engines.

Which jump starter charges faster, the GT4000S or the GT6000?

The GT4000S charges slightly faster at 1.2 hours from 0% to 100%, while the GT6000 takes 1.4 hours. Both use 100W fast charging and come with a 100W car charger in the box. The difference is small, but if you’re in a hurry, the GT4000S gets you back on the road a bit quicker.

Can the GOOLOO GT4000S start a 12L diesel engine?

I wouldn’t count on it. GOOLOO rates the GT4000S for diesel engines up to 10L with its 4000A peak. If you try to start a 12L diesel, you risk draining the battery or damaging the unit. For 12L diesels, you need the GT6000’s 6000A peak power — that’s the right tool for the job.

Which GOOLOO jump starter has a bigger battery capacity?

The GT6000 wins here with a 27,000mAh battery versus the GT4000S’s 20,000mAh. That extra 7,000mAh means more jump starts per charge and more juice for charging phones, laptops, or other devices through the USB ports. The GT4000S still gives you 60 jump starts per charge, which is plenty for most people.

Are the GOOLOO GT4000S and GT6000 safe to use on modern vehicles?

Both units have 10 types of protection technology built in, including spark-proof circuitry and reverse polarity protection. I’ve used both on modern trucks and SUVs without any issues. The 3.2-inch LED screen on each one clearly shows when it’s safe to start the vehicle, so you won’t make a mistake.

My Final Verdict

The GOOLOO GT6000 is my clear winner for large diesel engines. With 6000A peak power handling 12L diesels and a 27,000mAh battery, it gives you the extra headroom you need when a big engine fights back. The GT4000S is still a solid runner-up for 10L diesels and below, offering a faster 1.2-hour recharge time and a more compact build.

If you’re on the fence, ask yourself what engine you’re most likely to jump start. If it’s a 12L diesel truck or RV, stop hesitating and get the GT6000 — that extra power will save you when nothing else will. For everything else, the GT4000S gets the job done and saves you some cash.

🥇
My Top Pick: GOOLOO GT6000

GOOLOO GT6000 Jump Starter 6000A 12V with 100W Bi-Directional...