I thought I was smarter than a 5th grader when I bought my first Leeboy motor grader. Turned out I wasn't. The machine sat on a site where it couldn't maneuver, and the next job needed more blade pull than it had. That mistake cost roughly $12,000 in rental fees for a second machine and lost productivity. I've since documented seven significant equipment selection errors — and this comparison is born from those scars.
If you're debating between a smaller Leeboy grader (like the 635) and a larger one (like the 685 or 785), you're not alone. The decision looks simple on paper — bigger means more power, right? But the real cost isn't in the sticker price; it's in how the machine fits your specific jobs. Let's compare them across the dimensions that actually matter.
What We're Comparing and Why
We're looking at Leeboy's smaller-frame graders (models like the 635) versus their mid-to-large-frame graders (like the 685, 785, and 8500). Both are reliable — I've used both on dozens of projects. The question is which one prevents the rework and idle time that eats your margin.
I'm not a logistics expert, so I can't speak to the fleet shipping costs. What I can tell you from a project superintendent's perspective is how these machines behave in the dirt.
Dimension 1: Maneuverability vs. Raw Power
Small (635) — the tight-spot specialist
The 635 has a shorter wheelbase and tighter turning radius. On a residential street job with cul-de-sacs and driveways, it's a dream. I once used a 635 on a subdivision with 30 lots — we finished grading in 11 days with no need for a skid-steer to clean up corners. The machine's weight is around 12,000 lbs, which means less ground disturbance on finished base courses.
Large (685/785) — the production beast
Jump to the 685 and you're looking at 20,000+ lbs and a longer blade. It can move material faster on wide highways or large commercial pads. But put it in a tight residential lot and you'll spend half the day backing up. I watched a crew waste 3 hours on a 0.5-acre site because their 785 couldn't make the turns.
The verdict: If your average job site is under 2 acres with obstacles, the small grader wins. If you're doing miles of road, the large grader pays back. The mistake I made? I bought the 635 first, thinking it would handle everything. It didn't — I ended up renting a larger machine for highway work. That $4,200 rental fee could have been avoided.
Dimension 2: Operating Cost & Fuel Efficiency
This is where the 'bigger is better' myth hits hard. The 635 burns roughly 2.5 gallons per hour under moderate load. The 685? About 4.2 GPH. Over a 2,000-hour season, that's 3,400 gallons difference — at $4/gal, that's $13,600 in fuel alone. I've seen contractors who bought the bigger machine rarely run it at full capacity, effectively wasting 30% of fuel.
But wait — the large grader does finish a job faster. On a 10-mile county road resurfacing, the 685 completed the grading pass in 5 days vs. 8 days for the 635. The fuel cost per mile was actually lower for the large grader because of the speed advantage.
The verdict: For high-volume, long-stretch jobs, large grader wins on total cost per mile. For scattered, smaller projects, small grader's lower hourly burn dominates. Don't make the mistake of only looking at hourly fuel rate.
Dimension 3: Blade Precision & Finish Quality
Here's something that surprised me: the smaller 635 often produces a better finish on detailed work. Its lighter weight and responsive controls let you dial in tenths of an inch. On a parking lot slope job last year, we had to meet a 2% cross slope tolerance. The 635 got it in spec on the first pass 70% of the time. The 685 needed two passes 40% of the time because the operator had to 'feel' the heavier machine.
That said, on large flat slabs, the long blade of the 685 creates fewer passes and a more consistent plane. It's like using a 6-ft level vs. a 4-ft level — longer reference reduces local bumps.
This gets into operator preference territory, which isn't my expertise. What I can tell you from a practical standpoint: if your crew has one operator who's a wizard, he'll prefer the machine he's comfortable with. The 635 is easier for less experienced operators to handle without creating washboards.
Dimension 4: Maintenance & Part Availability
Leeboy parts are well-supported through their dealer network (a big advantage over some competitors). But parts for the 635 and 685 overlap about 60%. The unique components — like the 685's larger transmission — cost more and are less commonly stocked. I waited 8 days for a 685 axle seal last year. That was 8 days of downtime on a critical project.
For the 635, I've never waited more than 3 days for any part. Why? More units in the field = more dealer inventory. Simpler system = faster replacements.
The verdict: Small grader wins on part availability and lower repair costs. If your operation can't afford multi-day downtime, the 635 is safer.
So What Should You Choose?
Here's the straightforward advice I give my team now (after learning the hard way):
- Choose the small Leeboy grader (635) if: Your jobs are mostly under 3 acres, you have mixed site conditions, operator skill varies, or you value low hourly operating cost.
- Choose the large Leeboy grader (685/785/8500) if: You do miles of highway/runway grading, have experienced operators, and can keep the machine running continuously on big projects.
- Consider having one of each if your fleet needs flexibility. Many contractors run both — the small one for finish work and the large one for bulk earthmoving.
Don't forget that Leeboy also makes excellent asphalt pavers. If your surface job involves paving, pairing the right grader with a Leeboy paver can streamline the whole operation. But that's a separate comparison.
Oh, and about that dewalt air compressor — it's great for powering your nail drill on site, but it won't fix a grader selection mistake. Get the machine right first.
"5 minutes of verification beats 5 days of correction." — My checklist has prevented at least 7 mis-specs in the past 18 months, saving roughly $9,800 in potential rework.
Pricing note: The 635 is generally $15k–25k less than a comparable 685 (based on dealer quotes from Q4 2024; verify current pricing). That upfront savings can cover the rental of a larger machine for the occasional big job.
