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Infiniti M35/M45 Real World MPG



  • patpat Posts: 10,421
    Yeah, between Emporia and 85, but particularly in Emporia. Haven't ever been burned myself, but that's because I know too many people who have been. :sick:
  • james27james27 Posts: 433
    Overall, since I got the car, I've gotten just over 20mpg over 7.5K miles. This is mostly commute traffic (95% highway). Around here, highway runs 65-80mph. There's only one trip about 400 miles each way - essentially all on the interstate. The low was about 16 with a high about 24, most around 20. Right now, the computer is showing 20.4, and it is fairly close compared to the odometer and what it takes at the gas pump. I'd like a little more from it, but considering the relative power available from the RPM at cruise, I guess more is not forthcoming.
  • drtraveldrtravel Posts: 395
    I've driven close to 19K miles on my M35 and have average 18.90 MPG - actually calculated this myself. According to the trip computer I average 27 mph during my driving - I estimated 50% highway/50% around town.

    My gas gauge isn't very accurate but I know I go between 300 and 350 miles between fill-ups.
  • arwilliarwilli Posts: 4
    I never cared about gas mileage before until the skyrocketing prices and the MPG on my M. The computer says 15 MPG for my 1,200 miles (50/50 city/highway). Cost me $64 to fill up the tank this week so I actually found myself driving my wife's Sentra to run some local errands.
  • james27james27 Posts: 433
    The M gets lousy around town mileage in stop and go or short trips. Yesterday, I filled up and then got right on the read 22.8mpg when I pulled into the garage. There was a short wait at the entrance and exits. This was at around 70-75 mph.
  • sfcharliesfcharlie Posts: 402
    I've driven 2700 miles with a new M35. I once got close to 300 miles before computer and gas gauge said I needed to fill up. Each tank of gas is used for 75% highway/25% city driving, and maybe 1/4 of that highway driving has been stop and go. MPG has hit right at 18.1 once. All other fill-ups have been between 17 and 18 mpg. If I don't very consciously light-foot it, the mpg will drop close to 17.

    Among the worst figures for a 275 HP V-6.
  • james27james27 Posts: 433
    I've averaged just under 20mpg with an M35x over about 8K miles at about the same percentage of highway/city mileage. You can go fast, but smooth makes a huge difference in minimizing the fuel. No sense in running up behind someone and then having to use the brakes - drive ahead as far as you can, and do it smoothly, and you'll be surprised how much difference it makes. I've hit 400 miles on a tank on a trip with a couple of gallons left when I filled up. From my experience, it comes out about a wash in mileage/cost to use premium vs regular...I get better mileage with premium.
  • sfcharliesfcharlie Posts: 402
    Two different reactions: (1) thanks for the tips and the upbeat attitude. (2) I'm at a support group for parents of handicapped engines.

    Every single auto mag article comes in at 17 in mixed use. High percentage of people on this site say the same. Or read Edmunds consumer-reviews pros-and-cons for this car -- major "con" is poor mpg. It's not an illusion.

    I don't want driving my car to be an olympic consciousness raising event in order to approach 20 mpg with a V-6 engine in mostly straight 60-65 mph driving.

    Nonetheless, I have been so bothered by the mileage that (in addition to using premium) I don't rush around like an adolescent with his first car or even a person enthusiastic about driving. Smooth has become a religion. The car ain't converting, however.
  • acerfanacerfan Posts: 11
    I am currently looking to buy/lease one of these. I have two questions; don't cars give better mileage after being driven a few thousand miles (my Accord did after about 10,000 miles), and, does anyone have the numbers for the M45? Thanks.
  • sfcharliesfcharlie Posts: 402
    From: - - ll/

    "Test M35 averaged 16.4 mpg in city/highway driving, test M35x averaged 17.4 with more highway use. Test M45s averaged 16.0 in city/highway driving, 18.8-19.1 mpg in mostly highway use."

    Since I buy my cars new, I am comparing my first 3K miles with my M35 to similar experiences with other cars. I do expect the mpg to improve over time ... but ... I think much evidence has accumulated (in CR's evaluation, in reports from consumers on Edmunds, on this board, in many reviews, etc) to strongly suggest that V-6 engine/transmission gets poor mileage for a V-6. It has been widely recognized that the 5 gears and the gearing setup (designed to make this 275 HP engine, with torque of 270 @ 4800 rpm) accelerate faster than competition in auto reviews) produce unusually poor mpg. The car is so loveable in other ways and MSRP'd so much lower than competition that, I believe, people who are smitten by it have a tendency to simply not believe that it has any negative characteristics.
  • FYI - the manual states minimum 87 octane gas is required for the M35, not premium gas. Premium is suggested for increased performance on M35. I never noticed a difference, so I save my money and pump regular unleaded. Maybe the only way to notice a difference in engine performance is to drive it harder, and with a lead foot, but that would defeat the whole purpose of getting better mileage, right? Save your money and pump regular. My 2 cents.
    I think the M45 requires premium.
  • james27james27 Posts: 433
    You're right, the M35 allows use of regular, but they state that for full performance to use premium. I DO notice a difference. I also notice that I get better mileage with the premium, so the difference in actual cost per mile is about a wash.

    The M45 REQUIRES premium. They also state that if you MUST put in regular because premium is not available, to not fill the tank, only put in enough to get safely to where you can get premium, then fill it up so you boost the octane as much as you can. They also say to not drive aggressivly while you have the regular in there.
  • sfcharliesfcharlie Posts: 402
    "FYI - the manual states minimum 87 octane gas is required for the M35, not premium gas. Premium is suggested for increased performance on M35."

    Yes, I've been aware of that from before I bought the car. It was one factor predisposing me to choose the M35. However, like, James, I found that my mpg went down to 16 on regular, even though I've been so preoccupied with the mpg of this car that I have driven it with an obsessionally light foot, so much so that it begins to take the pleasure, for me, out of driving it. I have enjoyed, with other cars, driving a tank-full with total focus on higher-mpg driving, but I don't like being preoccupied with "Will this car ever get 20 mpg?" For example, over the weekend we drove early Saturday morning on a traffic-free route, all highway, for an overnight event, and back early Sunday in similar conditions. Steady 65 mph -- yet only got 19 mpg, for total 65 mph cruising, no city at all.
  • james27james27 Posts: 433
    What's your tire pressure? The alarms don't go off unless it gets fairly low. 36 all around isn't a bad number. At steady speeds it really does approach the epa ratings as long as you keep it under 80. On a long trip, the cruise control helps, too.
  • sfcharliesfcharlie Posts: 402
    "What's your tire pressure?"

    I keep a tire inflator in the trunk. I monitor the tire pressure every day on screen. I keep the cold pressure between 34 and 36. Do you think I should keep the cold tire pressure higher?
  • james27james27 Posts: 433
    That should be okay...are you at high altitude? That can make a difference in your performance and mileage. I guess I may be the exception...I usually get better mileage than average.
  • sfcharliesfcharlie Posts: 402
    I think you might be an exception.

    Here's a recent post from another Edmunds forum on real world sedan mileage ...

    "I am looking for any suggestions--I have a two year old G35x and have finally had it with the horrible milage I am getting. I do primarily suburban short hops of one to three miles with a small amount of highway driving when I can. I do not drive aggressively. I am getting around 13-15 MPG."

    I find a consistent pattern of talk/complaint about Infiniti V6 mpg across the internet. For example, quickly check the consumer ratings link at the top of this forum page.
  • blov8rblov8r Posts: 567
    Charlie .... You're car's powered w/ the same V6 as my M35, and my driving habits are very much like yours. I've NEVER gotten less than 16.4 mpg and that's with the summer blend here in AZ. If you're in San Fran and dealing with those hills your mileage comes as no real surprise. If you're driving on flatland, then something's amiss IMO. Bart
  • sfcharliesfcharlie Posts: 402

    That's likely ... the hills, I mean. You understand, I wasn't saying I've ever gotten below 16 mpg. That quote was from another post. But, you sound OK with a V-6 using 16-17 mpg than I am. It's subjective, individual variance at that point. I'd not complain about a V8 using 17 mpg, even in combined city/highway, but I'm sure the next generation V6 from Nissan will address this.

    Anyway, the mpg issue is probably getting some negative emotional overflow from my not liking the M35 as much as I thought I would -- aesthetically, mostly, but some of its driving characteristics as well ... not anything that would lead me to tell someone who likes the car "Don't; you'll regret it" but that has led me to explore pathways (I think I've found one I can live with) out of my lease and into another car, I hope, soon. I don't like feeling this way about my car, especially when, objectively, it's a good car.
  • mwgmwg Posts: 28
    Recently took my first highway trip with my M35X. Set the comnputer when I got on the highway and read it when I got off. So it was all pure highway mileage. To my suprise I got 27 MPG.Use top grade gas and have driven the car only 1700 miles. Suprised because our normal driving is 1 and 2 mile trips to supermarket,barber,friends, etc. during which we get mileage as low as 10-12MPG.

  • Drove from LA to Las Vegas last week. MPG was 24.5 driving at 75 - 80 MPH on cruise control.
  • blov8rblov8r Posts: 567
    My last car was a Caddy DeVille ... 28 mpg on the hiway @ 75 mph. Can't touch that w/ my M. Doesn't matter ... just a comment. Bart
  • cdnpinheadcdnpinhead Forest Lakes, AZPosts: 4,142
    It's mostly about RPM at cruising speed.

    That and ULEV.
  • Bought M35 non-sport in January 2006. Great car! Learned to manage my foot on the accelerator, it's a habit now, although somewhat disconcerting when I have to drive a rental car during an out of town business trip. Use premium gas. Get right at 18 mpg, with 50% city street driving. The other 50% is what I call metro-area hwy driving - meaning hop up on to an interstate, and drive 10-20 miles to get to another part of town. Have not done any true long distance hwy driving... i.e. hundreds of miles on a single trip.
  • I commute 28 miles one-way with about 20 being on the freeway. After 16 months the computer reads my overall average is 20.2 I always use premium fuel.
  • I have found that mileage is better if you use the manual shift mode. The D (automatic setting) always keeps the gear in position for maximum performance. For the best mileage, it is best to keep the car in 4th or 5th gear. Manual mode lets you select higher gears at the expense of acceleration (though it is still plenty of power for everyday driving).

    And when you want the max performance you can manually select lower gears.
  • I have an '06 M35x and I am getting 19 mpg. I have only checked gas mileage twice in 10,000 miles.

    Prior car was a 2003 M45 and I got 20 mpg. Not unhappy but I did think my gas mileage would go up with the new one.

    On another subject, the M45 was terrifying in the snow and M35x is a beast. Very happy.
  • shmangshmang Posts: 297

    Are there any M45 owners (prefer over 1 year old, so it shows broke in gas mileage) that can share their gas mileage as well as the driving style and city/highway %.

    I have a M45 and it seems that I basically get same city or highway, which is around 20 (say 18.5 city and 20.3 highway). Is this normal?
  • tayl0rdtayl0rd Posts: 1,926
    Dang! You couldn't wait until Feb 8 to ask that question? :cry: We were headed full-on into 2 years of nobody caring about the gas mileage of this car! :P
This discussion has been closed.