• Gas vs. Diesel: Cold Start Battle – Which Starts Quicker? [Video]

    Gas vs. Diesel: Winter cold start test

    Winter has a firm grip on much of the United States and the world. Colorado is going through a cold spell, and we wanted to see how some of our trucks would start after being parked for more than a day in temperatures that hover near 0 degrees Fahrenheit.

    Participating in this battle are Andre’s 2002 Chevy Silverado 2500 HD Duramax with a 6.6L Duramax V8 and TFLtruck’s 1985 Chevy K10 with a carbureted 305 cu-in V8. The Duramax does have an engine block heater, but we did not use it over night for this particular cold start test. Diesels have a problem with jelling fuel at temperatures below 32F. This is why all modern diesels (including the 2002 Duramax) come equipped with glow plugs. Diesels do not have spark plugs for ignition, but the glow plugs are there to warm up each cylinder’s combustion area.

    The 1985 Chevy K10 does not have any special provisions for cold starts. It has a carburetor with automatic choke, and that’s about it.

    Which truck starts quicker at a temperature of around 5F? Get all the details in the video below.

    Andre Smirnov
    Andre Smirnov
    Andre Smirnov is an Automotive Enthusiast, Producer, Reviewer, Videographer, Writer, Software Engineer, Husband, Father, and Friend.

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    34 thoughts on “Gas vs. Diesel: Cold Start Battle – Which Starts Quicker? [Video]

    1. Not an overly surprising outcome, still interesting. A little surprised on the diesel start taking that long. Andre do you use winter additives in the fuel?
      Now I want to know how quick the 6.6 would start if it was plugged in at a 4 degree cold start up? Should level the playing field.

      1. My 2002 lb7 duramax has started at negative 20f without being plugged in, took a few cycles of the glow plugs and a little bit of cranking but did start.

        The block heater keeps the coolant near 100 degrees f so when plugged in it just fires up like a warm summer day.

    2. Actually that is incorrect. I believe diesel will start gelling in the 15 degree area. If you use a good anti gel additive it will keep you covered down to -20 or -30.
      The older diesels definitely start harder. The newest cummins ive been around in the cold is a 2012 and it started like an old diesel but ive got a 15 powerstroke and my boss has a 15 duramax and they pop right off in -20 weather sometimes significantly faster than some gassers

      1. My 2013 Duramax didn’t start up in the morning when it was -15 F. I forgot to plug it in. Easy to ignite gasoline at any temperature when you have spark plugs. Diesels can be hit and miss in the cold. Better to always plug them in.

    3. The other morning my 2015 vw tdi at -14 started in just a few seconds. Just got in it and hit the start button. Then got to work and the 6.7 powerstroke started just as easy. No furl additives or plug in. There is something not right with andre’s duramax if you have to cycle the glow plugs and take a couple attempts at cranking at 4 or 5 degrees above.

      1. The older ones start harder than the latest gen diesels. He may have a few glow plugs getting weak or burnt open.

        1. Any 6.6 duramax should have problems at 5 degrees F….. maybe if it was a 6.5 i can see it. Struggling at 5 degrees but not a 6.6. 5 degrees is not that cold for any 2000 era diesel.

          1. Hahaha…ever tried starting a 7.3 Ford? They stopped making those in 2003. Ever tried a 6.0 Ford? Those stopped in 2007. All would exhibit similar starting characteristics to Andre’s 6.6L.

            1. had both… 2000 7.3 in Aaska. At around -15 it would sound horrible for about 10 seconds but wouldnt take 3 cycles on the glow plugs or several attempts. 6.0 psd i had a 2006 in Idaho. No issues in single digit temps.

              Andre needs some new batteries, some new glow plugs and maybe the glow plug relay.

            2. Scott, you just got lucky. Sometimes they will start. Sometimes they won’t. If the fuel gels or waxes, it won’t pump into the engine. It’s got nothing to do with all the other bells and whistles on the engine.

            3. Incidentally I just started my 7.3L it has not started in a month. It did so on first crank.
              The batteries are new and the glow plugs checked “OK” back in Oct.
              My experience with the 7.3L IDI, is that if you keep batteries charged and glow plugs in good nick they will start reliably in single digit weather. Better yet to plug them in.

            4. Fuel wont gel unless you put #2 in all the time. #1 and blends are difficult to gel in temps that are seen in the lower 48. I would have to search hard time finding fuel in idaho that would gel at -20. Much like andre in colorado he is prolly using a winter grade diesel cause that is all that is available

            5. Im not sure that glow plug cycling really does a whole lot anyways. The plugs in my Jeep Liberty CRD will stay on from something like 20 seconds after the key turn and will continue to run for a little bit after the engine starts.

              I will say, my jeep has troubles starting. It will start but cranks a bit longer and idles rough, like its not firing on all cylinders. They were better when they had ceramic glow plugs, but those were replaced with steel tipped plugs after the ceramics started breaking off in the cylinders.

    4. Yeah im thinking he has week glow plugs or poor quality fuel.. several years back I was in winterpark Colorado with my 05 Duramax (no block heater) and it was -14 and started right up with remote start.. upon entering the cab I found my exploded energy drink I left in the night prior…

    5. Glow plugs are not to fix gelling diesel. It has nothing to do with that. They are needed to preheat the cylinder so that it will start off warm enough for compression to make enough heat to ignite the diesel. Andre thought his truck wasn’t getting enough fuel…but it was getting plenty. The problem was not enough heat in the cylinders. I’d guess a weak or failed glow plug(s) because typically the Duramaxes start well.

      Cummins does use a grid heater instead of glow plugs. Ford and GM use glow plugs. All the new diesels start as well or better than a car today. I started my 6.7L Ford this morning from snowmobile camp, it was zero degrees F, and it started instantly. They will idle up, however, to prevent wet stacking.

    6. I am a little surprised the Duramax started that hard. Not sure how much difference is between an 02 and a 06 but our 06’s started really easy in single digit temps. Just the other day i started up one of our Ford 6.7L’s and it was 2°F outside. Started right up. Anything with a HUEI injector hates the cold. With the experiences i have had with Duramaxs is they go through glow plugs. But it usually triggers a check engine light.

      Andre, you may check if your truck is like others but just because the glow plug light turns off does not mean the glow plugs turn off. It is just an indicator your engine should be ready to start. Many diesels will keep the glow plugs on even though the light is on.

    7. I agree in that it had plenty of fuel, there chamber just wasn’t warm enough to combust. I think the modern diesels have higher fuel pressure which helps cold starts. My 2011 Duramax starts right up every time in the cold.

    8. Not sure about Duramax but running a diesel 10w30 or 5w40 in the winter helps cold starts especially on an old 7.3l or 6.0

      1. Yes it is great for HUEI diesels because the engine oil is used to operate the injectors via pressurization of the high pressure oil pump. Common rail high pressure injector diesels can start just fine on 15-40. But the 15-40 does get thick for sure. I personally like using 5W40 full syn in diesels. A good blend holds up really well. Especially in a HUEI engine where the HUEI system breaks the oil down much faster.

    9. When I lived in upstate NY, my 01 Duramax started without being plugged in just fine at -25. Granted they sell a winter blend that is good to below -30. Wonder what blend is in your truck Andre. When I couldn’t plug in I normally cycled the glow plugs twice, but that was about it. Curious what else is going on there.

    10. Had an issue with my 16 duramax remote starting at -14 no block heater plugged in. Truck would fire up then shut right down. I noticed oil coming through the gasket where the oil filter seats to base. Not sure if dealer left the filter a little loose and loss of oil pressure caused an engine shut down or was it something else? I didn’t have any issues with it since the oil change until this. Past duramaxes ive had never had this issue.

    11. I’d like to know how old the glow plugs are and what brand.

      Are you running a anti-gel additive?

      Having owned a identical truck I can say it should fire up much much easier.

    12. Reminds me of my high school years, about 83 or so.’
      My Dad had a Dodge D50 turbo diesel 4×4 truck and I had a 55 Chevy pickup with a straight 6 and 3 on the tree.
      It was about 10 below one morning and my Dad’s truck wouldn’t start and neither would my Mom’s new Ford Thunderbird.
      I told my Dad my truck would start, “No way” he said.
      I went out, pulled the choke, hit the starter and it started right up.
      Let her warm up and off we went.
      She wasn’t pretty but she got the job done that day !

    13. My 06 v-10 popped over in handful of cranks at -25. Tho it sounds a little hollow under the hood. Lol

    14. What’s ironic to me watching this video is my 2015 F 150 wouldn’t start all weekend in my driveway with jumps and charging the battery overnight. It only had 13000 mi on it and Ford Roadside Assistance is only M-F 8-5. Seriously? A brand new truck?

    15. “Diesels have a problem with jelling fuel at temperatures below 32F.”

      What is “jelling”? Is that like jelly? Or is it “gelling”?

      Too bad the newbe doesn’t know how to start a carbureted motor, he should have pumped it tight away about 2-3 times.

    16. if it had been a 6.5 they would have more than likely had to plug it in and come back later. looks like Andre may be in need of a set of the newer ceramic glow plugs. then they retest to see how much better they will work over the ones that came on the 6.6 in 02.

    17. I’ve never had an issue starting my diesels, even unplugged, down to -35F a few hundred miles outside Fairbanks. 7.3L Ford, 3.0L Volkswagen, and a 1.9L Volkswagen. I run straight #1 diesel w/o additives (except the 3.0 VW to protect the HPFP). A top-condition battery is essential, and synthetic motor oil helps a lot. Andre’s truck should have started much better than that; I’d be guessing a marginal battery.

    18. Synthetic is a great in cold temps. We usually don’t get that cold in Indiana but a few winters ago it was -26F. I have my normal 5-20 synthetic in the 2010 Ram. Starting when that cold sounded no different than a normal warm start other than noise from the PS pump.

      Our 96 12V would cold start with no block heater sub zero no issue ever. I tried to minimize those occurrences without block heater. Cold starts with cold 15-40 dyno oil is terrible on an engine. Watch Youtube cold pour tests and you’ll never start sans block heater again.

      Carb cars start just fine in cold weather if they are in proper working order with a knowledgeable operator.

      My 360 with a hi po demon no choke carburetor will fire up close to zero with relative ease. Takes a while to idle without a choke but fires almost instantly and runs fine as long as you keep it around 1000 rpms for a minute or two.

    19. Glow plugs have NOTHING to do with gelling fuel. Their only purpose is to warm the intake air on a cold day to a point that when the air is compressed in the cylinders, there is sufficient temperature rise in the air inside the combustion chamber so the diesel combustion process can commence.

      Back in the early ’80’s I had a diesel VW. The secret to easy cold weather starting without a block heater was good glow plugs, winterized fuel and a strong battery. One winter I had 1 bad glow plug and it would barely start but still run (rather roughly) on 3 cylinders until the 4th cylinder had warmed sufficiently for combustion to take place. Depending on the outside air temperature, 4th cylinder kick in would take anywhere from 1-3 seconds after the engine had started and everything would smooth out. Fast forward to today, I no longer own the VW (it is probably in the big rust bucket in the sky) but I have a small Kubota tractor with a 3 cylinder naturally aspirated 0.8 liter diesel with mechanical fuel injection, just the my old VW. Last winter I had 1 bad glow plug and it too would start on 2 cylinders, then the 3rd would kick in. This fall, a second glow plug failed and it gave me serious starting problems at 40*F. Plugging in the block heater eliminated the starting problem for the time being until I could purchase and install new glow plugs.

      Utilizing a block heater in the winter saves serious wear and tear on the starter and battery and I credit it with giving me a 10 year service life of the battery before replacement (although I could have just been lucky). My VW would start, reluctantly, at -25*F without a block heater, but I utilize a block heater and the engines in the VW and Kubota will start like it was a warm summer day.

      Back in VW days, I was purchasing my diesel fuel at a local fuel out dealer. They told me that the “magic” temperature for non-winterized diesel fuel was 7*F. Below 7*, the fuel starts forming wax crystals (cloud point) that will plug your fuel pick up, fuel filter and injector nozzles. At that time winterized fuel was not “reliable” and if we ran into issues, we could thin it down with #1 fuel (kerosene) to lower the cloud point. VW was quite emphatic about not using pure kerosene since it doesn’t have adequate lubrication properties to protect the injection pump.

      Today, here in New England, the gas stations that sell diesel fuel typically have winterized fuel available from somewhere between mid November and mid December, depending on weather predictions. I got caught a couple of times the first winter I owned my VW with fuel starting to gel, leaving me with an engine that would idle at best, doing and the “diesel crawl” down the street or not start at all, forcing me to wait for a warmer day.

    20. Was there a puff of smoke when the duramax started. If there was fuel going into the cylinders it would have exited into the exhaust while he was trying to crank it and probably resulted in a big puff of white smoke once the engine finally caught. If this didnt happen then perhaps he wasnt getting fuel.

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