I'm preparing to make a long dive over the Thanksgiving holiday using a high mileage vehicle (Chevy 4.3 with 265k miles), and I am wondering if there are any curious/gimmicky maintenance suggestions I might consider.

With respect to vehicle's condition, the vehicle is running well so I have no immediate concerns. ::knocks on wood:: Also I'm aware of the fluid levels, and I will check air pressure in the tires prior to leaving.

I use MaxLife 5/30 high mileage oil, and I'm about 1500 miles into my current service interval, so I plan to get an oil change after the trip (it'll put me at about 4k miles on that oil).

It's worth mentioning that I intend to pull a trailer on this trip...empty on the outbound leg, full on the return leg.

All this said here's my question: Considering the length of this trip, is there any real benefit to applying fuel, oil, transmission, coolant, or other additives at the start of the trip? Since the engine is going to be burning consistently for several straight hours, is this a good time to run a course of fuel cleaners, for example, being that I will consume an entire tank of fuel in one session rather than allowing the additive's detergents to linger in the system over week or two, potentially damaging seals, etc.

Edit: Just to emphasize, this isn't a question about improving reliability, rather it's a question about maintenance.

Although I'm specifically asking about fluid additives, I welcome any tips relevant to long drive before and after maintenance.

  • 1
    I think it comes down to the simple question of, do you trust the vehicle. If this is a vehicle you've put a lot of miles on, you know what it's like. If you think it will make it, it probably will. If you have doubts, seek another vehicle to do the job. Commented Nov 13, 2017 at 17:32
  • @Pᴀᴜʟsᴛᴇʀ2 it's more a question of is this a good opportunity to do unique fluid maintenance, in a way that would be more effective or easier on the component parts than, say, adding fluid additives and letting them sit for weeks. As I'll be burning several tanks of fuel over 2k miles, and I intend to have an oil change when I return. As for the vehicle, I trust it for the trip, basically—but there are always caveats and unknowns.
    – elrobis
    Commented Nov 13, 2017 at 17:37

1 Answer 1


If your car is running well and you're happy with it I would leave it alone for the trip and just drive it. The most important thing is that your car gets you there and back without trouble, and additives are not likely to increase your car's reliability. Just the opposite in fact, putting anything out of the ordinary in your tank adds an unknown element which increases the risk something may happen you have to deal with. I personally would not put additives in unless I was going to remain near home, that way I'm near my tools and trusted mechanics if something goes wrong.

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    +1 adding in any "unknowns" - even if the "risk" is very slight isn't something I'd be doing for a trip of this nature. I'd just do the normal checks to make sure that all the fluid levels were where they should be before setting out Commented Nov 14, 2017 at 14:26
  • GdD this was an interesting take on the question in a respect I hadn't considered. Absolutely +1 for the meantime. However, I'm not actually asking about improving reliability...if you check my response to Paulster, below the question, I specified is this a good opportunity to do unique fluid maintenance........my initial thinking wasn't about reliability, but more like: If I'm going to be running the engine continuously for several tanks of gas, I wonder if it's a good idea to use any of those fuel system cleaners?? Does the thinking make sense?
    – elrobis
    Commented Nov 15, 2017 at 15:11
  • GdD I ended up taking your advice and not using any additives. While I had a more long-term maintenance mindset when I initially asked the question, your observation that additives could result in unwanted effects that might even compromise reliability during the trip was sobering, and so I opted not to do anything.
    – elrobis
    Commented Nov 27, 2017 at 20:39
  • I hope you had a good trip in the end @elrobis!
    – GdD
    Commented Nov 27, 2017 at 21:02

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