Forum Discussion
- fla-gypsyExplorerSo Ford publishes factual information and some people try to make something out of it? The tow vehicle forum is ridiculous and full of fanboys.
- 12thgenusaExplorerI think it's pretty much a non-issue. Yes your engine loses power. All that means is that you slow down a little or your transmission shifts into a lower gear sooner.
I've driven (towed) over most of the passes in Colorado. The interesting thing here (in the mountains) is that as you gain elevation, the roads generally become more twisty with many curves speed marked at 25 to 45 mph. The general speed limit is usually lowered as well as is I-70 approaching the Eisenhower tunnel. So what does all that extra power get you? You have to drive slower anyway.
If Ford is rating their vehicles at sea level, they do a disservice to the majority of drivers since other than people who live directly on the coast, who drives at sea level? - IdaDExplorer
N-Trouble wrote:
mabynack wrote:
Diesels are greatly affected by air density if they are naturally aspirated. The turbocharger is the key to higher altitude operations, whether it's gas or diesel.
Diesel implies turbo these days...
Can't even remember the last time a non-Turbo diesel was put in a truck. Early 90's?
'93 or '94 for Ford, I think. My dad had a 1990 regular cab long box 4wd F250 with the old pre-powerstroke diesel. It had pretty good power but it was nothing like a modern turbo diesel at all. I believe it had a 4 speed auto. It was a nice truck - XLT Lariat, which at the time I think was about as high end as they came (cloth seats, carpet, AC, AM/FM w/ cassette, power windows/locks...that was about it). - N-TroubleExplorer
mabynack wrote:
Diesels are greatly affected by air density if they are naturally aspirated. The turbocharger is the key to higher altitude operations, whether it's gas or diesel.
Diesel implies turbo these days...
Can't even remember the last time a non-Turbo diesel was put in a truck. Early 90's? - marcsbigfoot20bExplorerI just got back camping at 7500 ft.
I noticed that EGTs (exhaust gas temps) were much higher when slightly lugging the engine and not making boost yet.
Slightly lower boost level ~1-1.5 psi.
Less air made more smoke during turbo spool up, more lag.
This is a 2000 Ford 7.3 PSD
Less dense air will also affect cooling of rad, AC cond, trans cooler, intercooler, brakes, etc when comparing to the same ambient temps at sea level.
Our superbikes used to run hot or overheat easily up in Colorado Springs due to the lack of air density over the radiator, not removing enough heat. - IdaDExplorerInteresting that they used to reduce the combined rating and vehicle rating, and now they just recommend reducing the combined rating. The same language is used in the F150 and HD manuals, with no distinction between turbo vs NA or gas vs diesel.
- FordloverExplorerThe irony here is that Ford is the only MFGer to warn about reduced performance at higher altitudes, and make recommendations about appropriate weight capacity reductions depending on your travels. Yet they are the only full line truck manufacturer to offer turbocharged gasoline engines that don't lose noticeable performance at altitude.
By the way, this notice/suggestion has been around for a long time in Ford's literature. In the 2002 Ford Towing Guide, you'll find this:2002 Ford Towing Guide wrote:
High Altitude Operation
• Since gasoline engines lose power at a
rate of 3% to 4% per 1,000 ft. elevation, a
reduction in gross vehicle weights and
gross combination weights of 2% per
1,000 ft. elevation is recommended to
maintain performance. - LessmoreExplorer IIIn addition to power loss by non forced aspirated engines, I think Ford is also alluding to the fact that the severe terrain (as opposed to relatively less challenging prairie towing) in high mountain driving, also affects the towing capacity because of the extra loading/resultant strain on suspension components.
This is just not a Ford thing, it would affect all trucks when towing, IMHO. - mich800ExplorerThe article states this has been in the manual in prior years. But the article is also confusing because they talk about reducing GVWR but the language only speaks to GCVWR.
- mabynackExplorer IIDiesels are greatly affected by air density if they are naturally aspirated. The turbocharger is the key to higher altitude operations, whether it's gas or diesel.
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