Community Forums

golferdhm · 08-11-2005, 03:41 PM

I'm going to Colorado and Utah in a couple of weeks, and, as I recall, the regular gasoline sold in stations there is only 85 octane. Does the Vortec engine do alright with the 85 octane, or do I have to buy the mid-grade there, which is usually 87?

golferdhm · 08-11-2005, 03:41 PM

I'm going to Colorado and Utah in a couple of weeks, and, as I recall, the regular gasoline sold in stations there is only 85 octane. Does the Vortec engine do alright with the 85 octane, or do I have to buy the mid-grade there, which is usually 87?

rvten · 08-11-2005, 05:13 PM

I used it no problem that I noticed.

M&EM · 08-11-2005, 05:20 PM

I travel through Utah and other 5000' + elev.- states using 85 octane regular with no problem. I try not to have too much of this fuel remaining when I return to lower elevations. Never had pinging/knock or other indications of problems in 30,000 miles.

edgray · 08-11-2005, 05:44 PM

M&EM: being from the deep south flatlands below sea level, I'm ignorant about this lower octane gas. Are you saying it is OK to use in our 8.1L Vortec, but only when at higher elevations?? I'm headed up there for Labor Day, and thought I would need the 87 octane minimum.

Please eloborate, if you can help with my confusion. THANKS, ED

Trek-Cyclist · 08-11-2005, 08:20 PM

I was in the mountains 7,000 plus feet about two months ago pulling up 6 - 8% grades for 17 miles on several occasions and used the 85 octane fuel without any problems or lack of performance at all. I was told at Loves that the only difference was the altitude, meaning the 85 performs the same as the 87 at lower elevations.
Have a great trip, not to worry!
From Paso Robles, Ca. (wine country south)

DriVer · 08-11-2005, 10:07 PM

If you call Workhorse Customer Support they will tell you not to use anything less than 87 octaine. I have seen 85.5 and 86 octaine as regular out West here and I have chosen to use the 88 octaine or mid-grade gasoline if 87 isn't available.

I have had no problems and no regrets.

Quite by accident I did fill up with 91 octaine and let me tell ya pilgrim! .... that Vortec loved it. I swear to Jupiter that I did get better mpg but I'm not ready to pay the extra premium for hi-test.

Dsouthw524 · 08-12-2005, 03:23 AM

Driver,
You know that all Octane is is the resistance to pinging. Any perceived power increase is a product of other blending. It is possible that the "big oil" has decided to blend with more energy into the higher grades of fuel.

We have noted for years that the MH and 4 wheelers we have driven always work better when we get around Missouri and south. We have tracked the mileage on many trips over the years from MN and can prove this perception is real as far as MPG.

M&EM · 08-12-2005, 06:02 AM

Ed, There are several sources on the internet that describe octane ratings and the effects on engine requirements due to elevation increases. I don't remember any specific sites but just search for octane ratings. The message I got was that engine octane number decreases as altitude increases. At 5000 foot altitudes 85 was considered ok for sea level engine requirements of 87..

edgray · 08-12-2005, 06:27 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">but just search for octane ratings </div></BLOCKQUOTE>
Now why didn't I think of that?

THANKS, for all of the replys. ED

golferdhm · 08-12-2005, 01:54 PM

Thanks for all the replies. I think, given the price of gas these days, that when I am over 5000 feet, I'll stick with whatever they call regular. If that is 85 octane, so be it.

FrontRangeRVer · 08-14-2005, 12:11 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by DriVer:

Quite by accident I did fill up with 91 octaine and let me tell ya pilgrim! .... that Vortec loved it. I swear to Jupiter that I did get better mpg but I'm not ready to pay the extra premium for hi-test. </div></BLOCKQUOTE>

Pretty much a waste of money using higher octane...you wont notice any power increase...octane is a measure of engine ping....

we use 85 here where we live at 8600 feet elevation....if you buy anything higher at these elevations, you are (again) wasting your hard earned money...

8,600 feet elevation, Colorado

Alan554 · 08-14-2005, 05:25 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by DSouthw524:
Driver,
You know that all Octane is is the resistance to pinging. Any perceived power increase is a product of other blending. It is possible that the "big oil" has decided to blend with more energy into the higher grades of fuel. </div></BLOCKQUOTE>

I'm not sure what you mean by "blend with more energy into the higher grades of fuel", but the different grades of gasoline all have the same amount of energy content per gallon. There certainly can be mileage & percieved power gains by using higher octane fuels because most modern engines, including the 8.1L, have knock sensors to detect pre-ignition or "pinging". And just because you aren't hearing any pinging on 87 doesn't mean there isn't some going on and the knock sensor adjusts fuel & spark timing to protect the engine. Using higher octane fuel can eliminate some or all of those operating points and improve performance, if the added cost is worth it to you.

But, the 8.1L's fuel & spark maps are designed for nominal 87 octane fuel and the knock sensor won't magically transpose the maps to maximize the potential performance available with 89 or 91 octane. That would require a chip from an aftermarket supplier and they do their product validation after they have your credit card number.

wilanddij · 08-15-2005, 03:30 AM

While we didn't have the MH when we lived in SLC (~4200'), we owned two Chevys, a Subaru, a Ford, a Honda, a Nissan, a Suzuki, and a Jeep. All regular gas sold in SLC is 85 octane, and all these engines ran fine on it. Going south from SLC, I think you'll find the regular octane rating goes to 87 in St. George.