You are here: Forums SUVs Acura MDX Acura MDX gas questions

Acura MDX gas questions

23 messages,  Last post on Aug 24, 2008 at 10:43 PM

You are in the Acura MDX Forum. Your Hosts are steve_ & tidester

What is this discussion about? Acura MDX, Fuel System, SUV

Messages Page 3 of 3 1 2 3 Prev Next Last

Go To Msg # Search This Discussion

#19 of 23 Re: Acura MDX: gas octane by dave_nh Jul 24, 2008 (5:54 am)
Replying to: maraist (Jul 14, 2008 6:02 pm) I have a 2005 MDX. Each year, we (Wife and I) drive round-trip from New Hampshire to California at least once in June and once in December and have been doing so for three years, now (we are retired). Due to the outrageous gas prices, I thought I'd experiment and see if lower octane gas had any observable, deleterious effects on performance and/or mileage. I understand that when the knock sensor retards the spark to keep from pinging, the performance and mileage SHOULD decrease. A performance drop would not necessarily be an issue since even this model MDX provides far more power than we need. Although this "test" is hardly scientific, we have driven the routes enough times and the trip mileage is high enough that the results should be meaningful.   A few "test conditions": * I do the all but a few hours of the driving. * From NH to CA is usually straight out I90 - I80 and speeds are usually Posted+4mph. * In Ca, the MDX is used for everyday, around the town driving. * Coming back, we try and take different routes; we do a lot of sight-seeing. * MPG is always calculated by using the on-board computer. * Tires are Bridgestone Dueler H/L Alenza running 38 lps pressure. * Engine oil is Mobil 1   Until this June, we had always used 91 octane and the overall trip mpg was ALWAYS 22 mpg +/- 0.5 MPG. Remember, this is an average based on at least 7,500 miles per trip, usually over 8,000 miles per trip. And there was never an appreciable difference between Westbound and Eastbound.   This trip, I used "mid-range" octane exclusively on the way out and "lowest" octane on the way back (including a trip up Pikes Peak).   Results vis-a-vis MPG * The average mileage going out was 20.4 mpg using Mid-range octane. * The average mileage coming back was the same 20.2 mpg using the "lowest" octane..   Results vis-a-vis performance. * NO noticeable drop in performance and I was looking for one.   Gas savings on this trip was barely noticeable. In some states, the difference between Premium and whatever I was using was substantial (like California), in other states, not all that much. And when I found a station that was selling Premium for LESS than mid-range, the owner told me Premium was not moving well so he dropped the price.   As always, For What It's Worth,   Dave Replies to this message: upstatedoc (Jul 24, 2008 6:26 am) dave_nh (Jul 24, 2008 1:40 pm) sfbayer (Jul 24, 2008 3:19 pm)
#20 of 23 Re: Acura MDX: gas octane [dave_nh] by upstatedoc Jul 24, 2008 (6:26 am)
Replying to: dave_nh (Jul 24, 2008 5:54 am) Great post, we have a '04 MDX and get around 22 highway w/ 93 oct (no 91 here) What do you figure your net loss or gain was in terms of $$ using 87 vs. 91? Replies to this message: dave_nh (Jul 24, 2008 1:40 pm) sfbayer (Jul 24, 2008 3:19 pm)
#21 of 23 Re: Acura MDX: gas octane [upstatedoc] by dave_nh Jul 24, 2008 (1:40 pm)
Replying to: upstatedoc (Jul 24, 2008 6:26 am) My guess (unfortunately, I did not keep all of my receipts) is that I probably saved enough over the roughly 8,000 miles to pay for our dinner for two in Ted's Montana Grill in Colorado Springs. Best Bison meat I have ever had!!   I notice that in our area (Southern New Hampshire), lately, prices are dropping and the difference between premium and regular is shrinking. I will go back to Premium.   As an aside, I also own a 2001 Mercedes E320 4-Matic. The drop in mileage from using premium to regular is significant to the point where it is more expensive to use regular than premium. Performance also drops off. Clearly, MB squeezes as much out of their engine designs as possible.   Dave Replies to this message: sfbayer (Jul 24, 2008 3:19 pm)
#22 of 23 Re: Acura MDX: gas octane [dave_nh] by sfbayer Jul 24, 2008 (3:19 pm)
Replying to: dave_nh (Jul 24, 2008 1:40 pm) Hi Dave,   Thanks for the information. I just brought a 2008 MDX three weeks ago. I have been using only 91 octane gas and has been able to get 18 MPG around town and 23 MPG highway.   The price difference between lowest grade (87 octane) to highest grade (91 octane) in California is usually $0.20 which is less than 5% saving. It is clear that the best option is to use Premium gas as there is a 9% reduction in MPG by using lowest grade (87 octane) based on your average 22 MPG using Premium and 20 MPG using 87 octane.
#23 of 23 Re: Leaded fuel for MDX 2004 [sarlek] by hotrodsurplus Aug 24, 2008 (10:43 pm)
Replying to: sarlek (May 04, 2008 4:16 am) Additives will not help this issue. The lead will render the catalytic converter junk in very short order (it will coat the catalyzing medium). You may be able to remove the catalytic converter(s), but ONLY IF there are no oxygen sensors downwind of the cats.   If the MDX has o2 sensors downwind of the cats and you remove them, the ECU will cause the engine to run poorly (generally lean or too little fuel which will reduce power significantly and destroy internal components).

Messages Page 3 of 3 1 2 3 Prev Next Last

Go To Msg # Search This Discussion

You are here: Forums SUVs Acura MDX Acura MDX gas questions