ALSN vs BWA: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of September 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. ALSN and BWA share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined ALSN and BWA exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

Allison Transmission Holdings, based in Indianapolis, designs and builds fully automatic transmissions and propulsion systems for on-highway trucks and buses, off-highway equipment, and defense vehicles. It is the clear global leader in medium- and heavy-duty automatic transmissions, with a large installed base, strong aftermarket parts and service revenue, and deep relationships with truck makers like Daimler, PACCAR, and Traton. The company also sells electric propulsion products such as its eGen axle line and remains a long-standing supplier of tracked-vehicle transmissions to the U.S. military and allied defense programs.

Full ALSN guide

BorgWarner makes the parts between an engine or a battery and the wheels. Four reportable segments carry the business: Turbos & Thermal Technologies (~$1.44 billion of second-quarter 2026 sales), Drivetrain & Morse Systems (~$1.45 billion), PowerDrive Systems (~$658 million) and Battery Energy Systems (~$100 million). Split a different way, management separates Foundational products, which touch internal combustion and hybrid powertrains, from eProducts, which touch electric ones. Foundational was ~$2.99 billion of the ~$3.65 billion quarter and eProducts ~$663 million, so roughly four fifths of revenue still rides on engines. Geographically the business is genuinely global rather than American: first-half 2026 sales split ~$2.65 billion Europe, ~$2.29 billion Asia and ~$2.07 billion North America. Customers are vehicle OEMs, which means BorgWarner's volumes are set by other people's production schedules.

Full BWA guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• ALSN drivers: Off-Highway acquisition scale-up; Defense strength.
• BWA drivers: Margin repair without volume growth; Turbos and drivetrain remain the cash engine.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: Allison's core on-highway transmission business is cyclical and fell about 4% year over year even as total revenue surged, so a downturn in North American Class 8 and vocational truck demand would pressure the highest-margin segment. For BWA, auto suppliers do not control their own volumes, and BorgWarner's revenue is set by OEM build schedules that can be cut with little notice.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick ALSN if you believe its drivers more; BWA if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the ALSN and BWA guides.

ALSN. First-quarter 2026 revenue of roughly $1.41 billion beat expectations, but most of the growth was inorganic from the off-highway acquisition while the core transmission unit declined about 4%. Full-year 2026 guidance calls for revenue of roughly $5.58 billion to $5.93 billion and adjusted EBITDA around a 25% midpoint margin, including more than $100 million of one-time integration costs. The stock's mid-teens to high-teens earnings multiple sits above its own long-run median, reflecting the expanded, more diversified revenue base.

BWA. Headline valuation looks contradictory: a ~35x trailing GAAP price-to-earnings ratio against a ~$14.1 billion market capitalization sits beside guidance that implies roughly a mid-teens multiple on adjusted earnings. Reconciling the two comes down to 2025 charges, including ~$42 million of impairments and ~$32 million of costs to exit the charging business, which depressed the trailing base without reflecting current run-rate profitability. Free cash flow near ~$1.19 billion, or roughly 8% of sales, is arguably the cleaner read on what the business earns.

Headline figures (approximate, July 2026): ALSN shows revenue (ttm) ~$3.9B, fy2026 revenue guidance ~$5.58B to $5.93B, q1 2026 revenue ~$1.41B (+84% YoY), q1 2026 adjusted eps ~$2.57; BWA shows revenue (ttm) ~$14.34B, net income (ttm) ~$415M, gaap eps (ttm) ~$2.00, 2026 adjusted eps guidance ~$5.05 to ~$5.30.

ALSN and BWA are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined ALSN and BWA exposure against your real portfolio. It is not an investment adviser.