Of all types of string trimmers, gas models are the most powerful. These are best for large properties where a cord won't reach fence lines and a cordless battery doesn't last. For extra-tough weeds and grass, experts recommend a heavy-duty model with dual cutting lines. However, gas trimmers are harder to start than electric models, and there's the added maintenance, mess and emissions that dealing with a gas engine entail. If you have a more modest property to keep trim and neat, a cordless electric string trimmer, or a corded electric string trimmer might be worth considering instead. Those are covered in their own sections, elsewhere in this report.
Among gas models, experts and users are near unanimous in their praise of the Echo SRM-225 (Est. $200), a straight-shaft weed whacker with a 17-inch cutting path and dual cutting lines. In one large comparative test, it excels in all cutting tasks. Editors note that the two cycle, 21.2 cc engine is certified to meet emissions standards for 300 hours -- well above the more typical 50 hours found with other gas-powered trimmers, and add that those standards suggests that the engine should prove to be more durable overall. Their conclusion is buttressed by a long five-year consumer warranty, or two years for professional use.
At Popular Mechanics, Roy Berendsohn tests the Echo SRM-225i (Est. $220), identical to the Echo SRM-225 save for an upgraded starter, in a six weed eater torture test to see which one would run the longest without losing effectiveness, and the Echo prevails. "The Echo began the test with some vibration, but it settled in nicely and ran smoothly, cutting with nearly explosive power and torque," Berendsohn says. "As its performance improved, we just drove it harder and harder until it outran everything else along the horse fence."
Users are even more impressed, it seems. Though the totals at HomeDepot.com include reviews originally left at the Echo web site, and reviews of the Echo SRM-225i and a version of this trimmer that's only sold in California (to meet that state's more stringent emissions regulations), the 4.7-star rating based on more than 2,100 cumulative reviews speaks for itself, as does the fact that 95 percent say they would recommend the SRM-225 to a friend.
In addition to excellent performance, and excellent expected durability, ergonomics are above average for a gas weed eater, though there are some things to be aware of. It's relatively heavy at 12 pounds, for one thing. The straight shaft makes this a good choice for taller users, and can reach further under bushes and brush than you could with a curved-shaft trimmer, but can make wrangling this string trimmer more challenging for petite users.
If you'd prefer a gas string trimmer that's a little lighter, a little cheaper and has a curved shaft instead of a straight one, the Stihl FS 40 C-E (Est. $150) looks like a good alternative.
With a 27.2 cc engine, a 15 inch cutting swath, and dual trimming lines, it's got plenty of power for most tasks. Rated at 9 pounds (minus the deflector and cutting attachment), experts say it's smooth to handle. Kudos are also given the spring-assisted pull starter, which makes for less effort when firing up this weed whacker. In comparison testing it earns the highest possible ratings for trimming (including trimming tall grass and weeds) and edging. The low exhaust motor exceeds EPA and/or CARB standards. Though Stihl markets this weed eater as a homeowner tool, for occasional use, its two year warranty applies to professional use as well.
Because Stihl markets primarily through local dealers and garden centers, user feedback is hard to come by, but we found roughly 160 reviews at the Stihl site. We don't normally put as much stock in reviews at makers' sites, but Stihl uses a third party service to ensure that reviews are authentic, and there are enough negative reviews for products posted that we are confident that no filtering is going on. With that out of the way, the 4.5 star rating for the FS 40 C-E indicates a high level of owner satisfaction. Some report say that they've had this trimmer two summers or more and that it is still going strong.
If your budget is tighter still, we found a few gas weed eaters that fare decently with experts. Finding one that users don't detest proved to be a lot tougher. With that caveat in mind, we find that the Ryobi RY252CS (Est. $100) is one budget gas string trimmer to consider. It's named a Best Buy in one large comparative review, and is one of the top-rated curved-shaft string trimmers overall in that test.
Despite the low price, this 25 cc, 17-inch weed eater is packed with power. Testing awards it top marks in all cutting tasks, including the ability to cut down tall grass and weeds without issue. It's part of Ryobi's Expand-It system, and can accept attachments such as a cultivator, blower and hedge trimmer. It's judged by the experts to be easy to handle and control; it's also quieter than most gas trimmers -- though that doesn't mean that ear protection is optional, only that it won't disturb neighbors quite as much. The trimmer is covered by a three-year warranty for home use, but only 30 days for commercial use.
User reviews are middling, but that's a step up from what we see with other gas weed whackers in this price range. It earns a score of 3.8 stars at HomeDepot.com, with around 77 percent of owners saying that they would recommend it. Some of the issues voiced by the minority that are less pleased seem to be related to problems that are common with gas trimmers -- though perhaps not common to those new to the challenges that a gas-fueled garden tool presents. A few also report receiving trimmers that were defective out of the box.