Hi All-

I'm moving to the mountains in a month, and I just sold my 2nd mid-life crisis car. So the D1 will be my daily driver until I figure out what to do next. I had heard a rumor before about not requiring premium gas at elevation. I'm going to be at roughly 6250'. Since it's California, even the "good" gas is 91. Can I get away with 89, or <gulp> even 87? My plan was to run a few tanks at 89 and then dabble lower. Anyone with experience? Like, what exactly am I looking for? I've never run non-premium in it and it runs pretty smoothly now.

 

Check out these two links that may help...


https://landroverforums.com/forum/di...s-worth-63984/

https://landroverforums.com/forum/di...cessary-10570/

 

Thanks. Those seem to cover the age-old argument about if you need premium or not. I'm on board with that and have always used it. My question is more about once you're at altitude. Per many different sites/posts/articles/etc., at higher elevation the barometric pressure is lower and the resulting fuel mixture is richer, negating the need for the higher octane. My question is really about anyone's personal experiences with a D1 and non-premium fuel at higher altitudes. I had run into a guy with a D1 and D2 up there and he told me "Fortunately at our elevation, you can skip the premium fuel, they run fine on 87 octane regular. "

So just wanted to see if anyone can confirm that anecdote. Google (if you care to...) "lower octane fuel higher elevation". My understanding is that the ultimate goal is to avoid pre-ignition/pinging, so that sort of answers my other questions about what to watch out for with lower octane fuel.

 

I read a recent contribution that said it depends on the engine management system. 96 on use GEMs with knock sensors. Prior to 96 do not have knock sensors, so either add octane booster additive or just use premium.

 

I live North of Denver (altitude 5100'ish) and I've always used regular fuel in my '96 with zero issues. I purchased this vehicle in Orlando, FL with 184k on the odometer and drove it for for 2 years there utilizing regular fuel. Old Indy now has 271k miles on the clock. I frequently travel to Estes Park and Rocky Mountain National Park with elevations up to almost 12k and have made multiple trips to Mount Evans, a 14'er, with no issues. My avatar photo is actually my Disco atop the apex of the paved road at Mt. Evans.

I average 16mpg and gas prices here are approximately $3.84/gal for regular and $4.49/gal for premium. At these current prices I've saved around $3500 over 87k miles using regular instead of premium. I paid $900 for Indy when originally purchased, so I could have purchased almost 4 more Indy's with the fuel savings. My old ride seems perfectly content burning regular fuel. Just my $3500.02 worth of advice.

 

BTW, regular in my area is 85 octane.

 

I'd be interested to know if you have tried premium going up the mountain to see if any performance improvement. Regular here is 87 octane, Premium 92.

 

Ya, I've tried it. My butt can tell no discernable difference, but my case may not be a good representation since my rig has 271k. No matter what fuel is in Indy, the elevation change on I-70 necessitates pressing the pedal to the metal and near redline for many, many miles. I'm always afraid the old beast is going to sling a rod. I tend to take shorter trips in Indy these days and utilize our CX-5 for longer excursions.

 

I have similar mountain highways here in southwestern British Columbia. I also use full throttle and near red line for numerous minutes at a time (D2 and P38). I think they can take it.

 

having driven my D1 on numerous cross-country trips - I did not really notice much performance difference with 87-92 octane - what I did notice was better mpg with higher octane - but as most stations now charge 50cents more per gal. for premium I did not find it worth the extra spend