gas tanks are practically never welded anymore, they’re usually made from blow-molded HDPE.
so what? in 1985 plenty of trucks were offered with the option of dual fuel tanks, and the dealer could install the second one after the fact. what does that have to do with a 2017 Colorado?
and I said nothing about room, I said they’re designed to nestle up to the frame rails and crossmembers. for a Silverado tank to fit in a Colorado, that section of the two trucks frames would have to be very, very similar.
oh, and by the way, the '85 Silverado had the “infamous” side-saddle tanks, which nobody (NOBODY) will do anymore.
OK, if the blow-molded HDPE gas tanks made by a particular supplier at a particular plant on a particular date were out of spec, the vehicle manufacturer needs to know which vehicles they were installed on, so they know which vehicles need to be recalled.
Extra fuel capacity in rank -
My father worked for many years as a mechanic at a GM dealership.To confirm others comments, he told me that GM’s and most cars always had about 10% more fuel capacity than they stated to allow people a margin of error when running low on fuel.
I have a Toyota that tracks “distance to empty” based on fuel available. When desperate, I’ve run on “zero kilometres remaining” for an additional 50km (anxious & white knuckled). That’s at least 10% more than my “full tank” capacity.
GM Substituting different parts
Many years ago I worked at GM for a time at an engine plant. They run “Just in Time” inventory and if there is any hiccup in supply, the costs are tremendous. This kind of “temporary” minor substitution happened all the time if we ran out of parts.
As Dewey noted, I suspect that there was supply problem with the 21g tanks (maybe quality, machine breakdown at the supplier, shipping delivery delay etc) and rather than shut the assembly line down, they substituted the 26g.
I think we’re presuming this was widespread, but it may have been the last 20 trucks at the end of the shift. Rather than lose the production and send 1000 employees home early with pay, they went to the 26g pallet and pulled 20 tanks out and substituted them.
I’m sure the cost to change all the paperwork etc for the 25 trucks would have been a pain in the butt, so they let it slide. I’m sure the logic would be “it’s only 25 trucks and we’re giving buyers a free upgrade they’d otherwise pay for. Who’ll complain?”
I don’t know how long “many years ago” is, but shit like this doesn’t happen today. if supplies of a part run out, the line stops and the responsible supplier starts accruing costs for every hour the line is shut down until they can get parts back in the pipeline.
An extra 10% would be about 2 gallons more, not 5.
Throwing on parts that aren’t spec and then not changing the specs, even for just 1 car, sounds super sloppy to me. What other parts are they doing that with?
I don’t see the bigger tank as an option on the Colorado. If the bigger tank fits why wouldn’t they offer that?
Because it isn’t really that big of a deal. It’s not even my goddamn truck.
Hey, BK, Theres a chance nobody knows the answer to any fof the freaking questions on these boards. But it’s always worth a shot to ask and maybe hear some interesting replies.
My comment on the extra fuel was just confirming what a couple others have said about them “thinking” that there is extra capacity in fuel tanks versus gauges. I agree, it doesn’t address your post. I should have been clearer on this.
You’re asking for speculation and I think my speculation is very plausible. In fact, I’m struggling to imagine any other scenario where this might have happened other than the one I describe. The idea this may have happened on a larger scale (hundreds of trucks?) or due to some design change is and still not be documented is really unlikely.
Yes, it’s sloppy to substitute compatible parts, and the GM plant where I worked (20 years ago) did it infrequently and only in emergency situations like the one I described.
I can imagine two other possibilities where this could happen as one-off incidences, both of which would be long shots:
If the fuel tank was damaged during shipment or prior to customer delivery at the dealer and the dealer made the decision to sub in a larger tank. “He’s coming for the truck tomorrow and it’ll take a week to get the new tank but we have a bigger one here…”. In this case though the dealer should /would have told your brother about getting the larger tank.
The tank may have been added as an after market upgrade for another buyer who backed out of the purchase and the dealer just left the tank on rather than swap it back. This kind of the thing does happen, but the dealer should have told your brother. @jz - yes the supplier gets the blame and cost if it’s their fault, but what if a GM tow motor driver or some other GM employee caused the issue? Would the plant manager, superintendent or supervisor take the blame and the hit on their bonus for missing targets? I don’t think so. The people I worked with were very smart and pragmatic. Sub in the bigger tanks on the 20 trucks, problem solved. A very pragmatic solution to a very short term minor but expensive problem.
The tank may have been added as an after market upgrade for another buyer who backed out of the purchase and the dealer just left the tank on rather than swap it back. This kind of the thing does happen.[/QUOTE]
It happened when I bought my Vett. Guy had all sorts of options put on it then, for whatever reason, didn’t take delivery. But everything on it was accounted for on paper when I bought it new but with the options at a tremendous discount.
Part of it may be in your style of filling the tank. If you quit filling when the nozzle clicks off, as the owner’s manual says, you won’t pump as much as the guy who keeps re-squeezing the nozzle and rocking the car back and forth to get the absolute last ounce in there. Car and truck tanks are designed with baffles inside to ensure a safe amount of “headroom,” or air space to allow for temperature expansion, barometric pressure changes, and the occasional owner who goes romping across rough ground to get to his favorite fishing spot. Under the hood, there’s a canister that recovers fuel vapors in the sealed system, and it depends on that headroom, so the recovered fuel can get back to the tank.
Of course, it’s possible that the dealer’s pump is malfunctioning, with or without the dealer’s intent. In my state, the Weights & Measures board has only 2 agents checking all the gas pumps in the state. Will they get to all of them this year? Maybe.
By the way, fuel gauges, after all these years, still work from a float, arm, and rheostat in the tank. The engine’s computerized fuel injection theoretically can tell itself exactly how much fuel it’s using, if everything is working perfectly, but the reader in the tank is still the same old float on a stick.
I doubt they would intentionally have a 5 gallon buffer. And anyway, I’m pushing 60. this isn’t the first vehicle I’ve pumped gas into. The answer, I’m sure, is they just put the bigger tank on. i’m just surprised they did so but kept the spec docs the same.
In most areas of Wisconsin counties and municipalities do the Weights and Measures enforcement, so there is plenty of checking happening. And remember, we filled up in two different areas and got the same result.