{"id":937,"date":"2025-12-13T16:58:57","date_gmt":"2025-12-13T16:58:57","guid":{"rendered":"https:\/\/www.sterlingcooper.info\/blog\/?p=937"},"modified":"2025-12-13T16:58:57","modified_gmt":"2025-12-13T16:58:57","slug":"gm-to-bring-back-the-two-stroke-simple-engine","status":"publish","type":"post","link":"https:\/\/www.sterlingcooper.info\/blog\/gm-to-bring-back-the-two-stroke-simple-engine\/","title":{"rendered":"GM TO BRING BACK THE TWO STROKE SIMPLE ENGINE?"},"content":{"rendered":"<div class=\"td-post-header\">\n<header class=\"td-post-title\">\n<h1 class=\"entry-title\">Is GM Bringing Back the Two Stroke?<\/h1>\n<\/header>\n<\/div>\n<div class=\"td-post-sharing-top\">\n<div id=\"td_social_sharing_article_top\" class=\"td-post-sharing td-ps-bg td-ps-notext td-post-sharing-style1 \">\n<div class=\"td-post-sharing-visible\">\n<div class=\"td-social-but-icon\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"td-post-content tagdiv-type\">\n<div class=\"td-post-featured-image\"><a class=\"td-modal-image\" href=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead-.jpeg\" data-caption=\"\"><img loading=\"lazy\" decoding=\"async\" class=\"entry-thumb\" title=\"Two stroke lead\" src=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--696x498.jpeg\" sizes=\"auto, (max-width: 696px) 100vw, 696px\" srcset=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--696x498.jpeg 696w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--300x214.jpeg 300w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--1024x732.jpeg 1024w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--768x549.jpeg 768w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--1536x1098.jpeg 1536w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--2048x1464.jpeg 2048w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--588x420.jpeg 588w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/Two-stroke-lead--1068x763.jpeg 1068w\" alt=\"\" width=\"696\" height=\"498\" \/><\/a><\/div>\n<div class=\"pf-content\">\n<div class=\"printfriendly pf-button pf-button-content pf-alignright\"><a title=\"Printer Friendly, PDF &amp; Email\" href=\"https:\/\/www.ericpetersautos.com\/2025\/12\/13\/is-gm-bringing-back-the-two-stroke\/#\" rel=\"nofollow\"> <img decoding=\"async\" class=\"pf-button-img\" src=\"https:\/\/cdn.printfriendly.com\/buttons\/print-button-nobg.png\" alt=\"Print Friendly, PDF &amp; Email\" \/> <\/a><\/div>\n<p>There are rumors afoot that <a href=\"https:\/\/ppubs.uspto.gov\/api\/pdf\/downloadPdf\/20250354528?requestToken=eyJzdWIiOiIwMzFlOTQyYy1hOTFmLTRhOWUtOTBmZS0yOGVkMjlmYmFjYzYiLCJ2ZXIiOiIyNTg3NzJlMC0wNjlkLTQ4NzItODE3OS0wOGEwNzU3NDQ4NDciLCJleHAiOjB9\">GM is developing<\/a> a two stroke engine, which is a type of engine not seen in cars (outside of the old Soviet Union) since before JFK was elected president.<\/p>\n<p><iframe loading=\"lazy\" title=\"YouTube video player\" src=\"https:\/\/www.youtube.com\/embed\/ws0FqRlw-_w?si=WSbQhXSZ_ihBGx29\" width=\"100%\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\" data-mce-fragment=\"1\"><\/iframe><\/p>\n<p>Two strokes have many virtues, including simplicity \u2013 because they have no valvetrain \u2013 and low cost (because they have fewer moving parts) and high output for their displacement, relative to a four stroke engine of the same displacement, because two stroke engines make power every time a piston ascends to top dead center within the cylinder. A four stroke engine has four strokes \u2013<em> intake, compression, combustion, exhaust<\/em> \u2013 but only one of those strokes (combustion) results in power.<a href=\"https:\/\/www.ericpetersautos.com\/2025\/12\/13\/is-gm-bringing-back-the-two-stroke\/screenshot-1213\/\" rel=\"attachment wp-att-135127\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-medium wp-image-135127\" src=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent-216x300.jpg\" sizes=\"auto, (max-width: 216px) 100vw, 216px\" srcset=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent-216x300.jpg 216w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent-738x1024.jpg 738w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent-768x1065.jpg 768w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent-1107x1536.jpg 1107w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent-303x420.jpg 303w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent-696x965.jpg 696w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent-1068x1481.jpg 1068w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-patent.jpg 1364w\" alt=\"\" width=\"216\" height=\"300\" \/><\/a><\/p>\n<p>Two strokes also have some strikes against them. The main one being they are very difficult to make compliant \u2013 with emissions standards \u2013 because for one thing they burn oil on purpose (it is mixed with the gas, to provide engine lubrication) and for another because the nature of the design allows for contamination of the intake charge with exhaust gasses. which is a function of using ports that are covered and uncovered by the pistons as they go up and down in the cylinders. Four strokes also have ports but they are opened and closed by intake and exhaust valves that seal when closed.<iframe loading=\"lazy\" title=\"YouTube video player\" src=\"https:\/\/www.youtube.com\/embed\/3OY6R_nGCp0?si=FOaweT6Htsh660nA\" width=\"100%\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\" data-mce-fragment=\"1\"><\/iframe><\/p>\n<p>There is also the related problem of piston ring wear caused by the piston going up and down in cylinders that have <em>holes<\/em> (those ports) in their sides. In a four stroke engine, the piston is surrounded completely by the cylinder wall, which compresses the piston and oil control rings evenly. In a two stroke engine, the open port on the side of the cylinder creates a spot where the rings are not compressed evenly, leading to faster wear and more blow-by (higher emissions). And that is why the only vehicles with two stroke engines that can still be legally sold are for use off-road only.<\/p>\n<p>These being off-road dirt bikes.<a href=\"https:\/\/www.ericpetersautos.com\/2025\/12\/13\/is-gm-bringing-back-the-two-stroke\/screenshot-1211\/\" rel=\"attachment wp-att-135111\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-medium wp-image-135111\" src=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-two-stroke-300x195.jpg\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" srcset=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-two-stroke-300x195.jpg 300w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-two-stroke-1024x666.jpg 1024w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-two-stroke-768x499.jpg 768w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-two-stroke-646x420.jpg 646w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-two-stroke-696x452.jpg 696w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-two-stroke-1068x694.jpg 1068w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/GM-two-stroke.jpg 1440w\" alt=\"\" width=\"300\" height=\"195\" \/><\/a><\/p>\n<p>But a two stroke may be coming back on-road. The may be part is suggested by a new GM patent for a new-design two stroke engine that appears to have a sleeve-valve or linear system that creates a hole-less cylinder wall when the piston passes by the port, thereby improving sealing and reducing premature piston ring wear \u2013 which will (or ought to) help reduce emissions and make the engine compliant.<\/p>\n<p>Maybe.<\/p>\n<p>But don\u2019t expect to see this engine powering a GM vehicle anytime soon \u2013 though it may be buried somewhere deep inside inside a future GM EV as a power source. More finely, as a generator, to produce the electricity you\u2019d otherwise have to plug in (and wait) to get. This would eliminate not just the Range Anxiety you have heard people talk about but the arguably more serious problem \u2013 Wait Annoyance \u2013 that is much less-talked-about. Few people would give a flip about range if it were easy to get more. Have you ever heard of someone complaining about the range of a Hellcat Charger? It has a range of maybe 200 miles, if you are easy on the accelerator pedal. If you aren\u2019t, you might burn up the contents of its tank in 150 miles or even less.<a href=\"https:\/\/www.ericpetersautos.com\/2021\/02\/16\/the-part-time-electric-car\/tesla-wait-2\/\" rel=\"attachment wp-att-93178\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-medium wp-image-93178\" src=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2021\/02\/Tesla-wait-300x206.jpg\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" srcset=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2021\/02\/Tesla-wait-300x206.jpg 300w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2021\/02\/Tesla-wait-100x70.jpg 100w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2021\/02\/Tesla-wait-218x150.jpg 218w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2021\/02\/Tesla-wait-611x420.jpg 611w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2021\/02\/Tesla-wait.jpg 626w\" alt=\"\" width=\"300\" height=\"206\" \/><\/a><\/p>\n<p>But it\u2019s not a problem because it\u2019s not a hassle to refill the tank. A five minute stop and you\u2019re ready to go. With an EV, the wait is best-case at least 15-20 minutes for a<em> partial<\/em> charge and that\u2019s just too much hassle for most people.<\/p>\n<p>Hence the idea of what\u2019s being marketed as a <em>range extender<\/em> by some purveyors of EVs. The range extender being a gas-burning engine. You never run low on charge because the engine is there to generate more as you drive \u2013 so long as you have some gas in the tank. That is the role GM\u2019s new two-stroke is likely to play, if it ever sees the light of day \u2013 which it just might because there are certain advantages, as detailed earlier. A two-stroke range extender would be cheaper and so help reduce the cost of the EV. It also takes up less space and it\u2019s simpler, all of that is good given it would likely be buried somewhere deep inside the EV\u2019s guts and for that reason not easy to service.<\/p>\n<p>Best to make it so that it needs service less often.<iframe loading=\"lazy\" title=\"YouTube video player\" src=\"https:\/\/www.youtube.com\/embed\/g3WawiITj3A?si=CG0sUlB64KbAsSaT\" width=\"100%\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\" data-mce-fragment=\"1\"><\/iframe><\/p>\n<p>This isn\u2019t a new concept, by the way. GM was first to market a range-extender equipped EV. It was called the Volt (old review of one is <a href=\"https:\/\/www.ericpetersautos.com\/2016\/06\/08\/2017-chevy-volt\/\">here<\/a>). It could be driven about 50 miles on battery power but when that was exhausted you did not have to stop for a charge because it could charge itself. Some people, at the time, confused the Volt with a hybrid \u2013 which it technically was. But it was very different from other hybrids because unlike them, the Volt was primarily an electric car that happened to have a gas engine on board. In conventional hybrids, the gas engine provides both charge and propulsion; i.e., it powers electrically powered accessories and\u00a0 the wheels that move the car. In the Volt, the gas engine was there chiefly to generate the electricity that powered the electric motors that turned the wheels.<a href=\"https:\/\/www.ericpetersautos.com\/2025\/12\/13\/is-gm-bringing-back-the-two-stroke\/contender\/\" rel=\"attachment wp-att-135112\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-medium wp-image-135112\" src=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/contender-300x225.gif\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" srcset=\"https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/contender-300x225.gif 300w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/contender-80x60.gif 80w, https:\/\/www.ericpetersautos.com\/wp-content\/uploads\/2025\/12\/contender-265x198.gif 265w\" alt=\"\" width=\"300\" height=\"225\" \/><\/a><\/p>\n<p>It was a fine idea with bad timing. The Volt came out in 2011, when there wasn\u2019t much market for such a vehicle and no mandated \u201cmarket\u201d for EVs. That came too late to save the Volt, which got cancelled after 2019 \u2013 just as the \u201cmarket\u201d for EVs began to pick up. To borrow a line from On the Waterfront, <em>it coulda been a contender<\/em>.<\/p>\n<p>The Volt wasn\u2019t obnoxiously expensive \u2013 as the EVs that came later were (and are) and it was practical. More so, arguably, than an engine-only car because it could run for 50 miles entirely on battery power. This gave it dual fuel capability \u2013 as well as very long legs. Some owners had to get into the habit of using fuel stabilizer because it took months to burn through a tank.<\/p>\n<p>It\u2019s ironic to reflect that the one EV that maybe made some sense got cancelled at just the moment when everything else began to make no sense at all.<\/p>\n<p>. . .<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Is GM Bringing Back the Two Stroke? There are rumors afoot that GM is developing a two stroke engine, which is a type of engine not seen in cars (outside of the old Soviet Union) since before JFK was elected president. Two strokes have many virtues, including simplicity \u2013 because they have no valvetrain \u2013 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-937","post","type-post","status-publish","format-standard","hentry","category-fossil-fuels"],"_links":{"self":[{"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/posts\/937","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/comments?post=937"}],"version-history":[{"count":1,"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/posts\/937\/revisions"}],"predecessor-version":[{"id":938,"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/posts\/937\/revisions\/938"}],"wp:attachment":[{"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/media?parent=937"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/categories?post=937"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sterlingcooper.info\/blog\/wp-json\/wp\/v2\/tags?post=937"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}