Poorer MPG than expected
#1
Poorer MPG than expected
Hi all,
I purchased my '12 XKR vert with 6500 miles on it last September, and have only put approx. 1500 miles on it since. I live and work in Chicago, so most of my driving (90%) is in stop-and-go traffic, and I rarely exceed 35mph (yes, I know; that really sucks for me). I only have occasional highway trips allowing me to open it up a bit.... but I don't exceed 75mph or so, and I almost always drive pretty mellow... no stoplight Grand Prix. I realize that my mileage suffers from stop-and-go, etc., but I'm still shocked at how horrible my fuel consumption averages out; between 8-10MPG! I don't expect 20MPG, but I thought it'd be much better than what I'm getting.
For those of you w/2010+ XKRs, do you think the MPG I'm getting is pretty much what should be expected, or does it seem low to you as well? My tire pressure is spot on, I burn only 92+ octane super, & my oil and fuel filters were supposedly changed by the dealer when I bought the car.
Any input is appreciated, and yes, I did a search prior to posting this up.
Thanks,
Steve
I purchased my '12 XKR vert with 6500 miles on it last September, and have only put approx. 1500 miles on it since. I live and work in Chicago, so most of my driving (90%) is in stop-and-go traffic, and I rarely exceed 35mph (yes, I know; that really sucks for me). I only have occasional highway trips allowing me to open it up a bit.... but I don't exceed 75mph or so, and I almost always drive pretty mellow... no stoplight Grand Prix. I realize that my mileage suffers from stop-and-go, etc., but I'm still shocked at how horrible my fuel consumption averages out; between 8-10MPG! I don't expect 20MPG, but I thought it'd be much better than what I'm getting.
For those of you w/2010+ XKRs, do you think the MPG I'm getting is pretty much what should be expected, or does it seem low to you as well? My tire pressure is spot on, I burn only 92+ octane super, & my oil and fuel filters were supposedly changed by the dealer when I bought the car.
Any input is appreciated, and yes, I did a search prior to posting this up.
Thanks,
Steve
#2
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intdiamond (03-14-2013)
#3
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intdiamond (03-14-2013)
#4
#5
True.... but I've tried for 3 tanks to drive like a grandma and still can't better 10mpg.... sounds close, but it's 30% less than you and others I've talked to who are getting 13-15mpg. Trust me, I didn't buy the car because I wanted great mileage, and I do love it; it just sucks down the gas much quicker than I ever thought it would. My pal's Lambo Murcielago gets 13mpg!
OK, I'll shut up now!
OK, I'll shut up now!
#6
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intdiamond (03-15-2013)
#8
How are you measuring the MPG number?
I drive 36 miles a day to and from work. At this time, I am not having to get on the interstates around/in Atlanta. I take back roads, and can't drive fast most of the time. I also get caught at several lights. I don't drive in "S" and Dynamic mode often. My trip computer says I am getting 17.1 MPG. This may not be accurate, but I only fill up once a week, and have about a quarter of a tank left when I do fill up. If I take a weekend trip then obviously I have to get more gas.
I know I am getting better than 10 MPG. My Ford F250 gets 12 - 14MPG, with a 5.2 L V8 and a heavier vehicle.
10 MPG seems to low to me.
I drive 36 miles a day to and from work. At this time, I am not having to get on the interstates around/in Atlanta. I take back roads, and can't drive fast most of the time. I also get caught at several lights. I don't drive in "S" and Dynamic mode often. My trip computer says I am getting 17.1 MPG. This may not be accurate, but I only fill up once a week, and have about a quarter of a tank left when I do fill up. If I take a weekend trip then obviously I have to get more gas.
I know I am getting better than 10 MPG. My Ford F250 gets 12 - 14MPG, with a 5.2 L V8 and a heavier vehicle.
10 MPG seems to low to me.
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intdiamond (03-15-2013)
#9
I go by both what the onboard computer tells me my MPG is and by my own calculations of total miles driven divided by how many gallons I put in the tank.... not the most scientific and accurate method, but close enough. The two numbers come out +/- equal each time, and I've done this for 7-8 tanks worth so far....
#10
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intdiamond (03-17-2013)
#11
In the FWIW department, here are my mileage numbers. I keep pretty good track of this stuff so I'm aware of how much this hobby actually costs me. /facepalm
Typically I seem to get around 14 or so. That's not stop n go morning commute traffic, but 35mph access roads and stop n go at stoplights in town. I do see 19 or so on the highway if I do a real freeway trip (convertible down takes it down an mpg or so). I... am not a light foot usually either. If I keep perf mode off and not click the knob to S I get better mileage.
XKR (Jaguar XKR) | Fuelly
Typically I seem to get around 14 or so. That's not stop n go morning commute traffic, but 35mph access roads and stop n go at stoplights in town. I do see 19 or so on the highway if I do a real freeway trip (convertible down takes it down an mpg or so). I... am not a light foot usually either. If I keep perf mode off and not click the knob to S I get better mileage.
XKR (Jaguar XKR) | Fuelly
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intdiamond (03-17-2013)
#12
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intdiamond (03-17-2013)
#14
I had a test drive last Friday of an XKR with the 5 litre SC engine, and Boy, did it go !
However the fuel consumption indicator was showing just over 18mpg based on the slightly larger UK gallon. When I gave it a short burst down a dual carriagway, the consumption dropped to 17.6 mpg.
I think it is your very low speed runs and short journeys that are hammering your wallet. Maybe you should buy a little town car to tootle around town, and keep the XK for weekends on the highways.
However the fuel consumption indicator was showing just over 18mpg based on the slightly larger UK gallon. When I gave it a short burst down a dual carriagway, the consumption dropped to 17.6 mpg.
I think it is your very low speed runs and short journeys that are hammering your wallet. Maybe you should buy a little town car to tootle around town, and keep the XK for weekends on the highways.
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intdiamond (03-17-2013)
#15
I had a test drive last Friday of an XKR with the 5 litre SC engine, and Boy, did it go !
However the fuel consumption indicator was showing just over 18mpg based on the slightly larger UK gallon. When I gave it a short burst down a dual carriagway, the consumption dropped to 17.6 mpg.
I think it is your very low speed runs and short journeys that are hammering your wallet. Maybe you should buy a little town car to tootle around town, and keep the XK for weekends on the highways.
However the fuel consumption indicator was showing just over 18mpg based on the slightly larger UK gallon. When I gave it a short burst down a dual carriagway, the consumption dropped to 17.6 mpg.
I think it is your very low speed runs and short journeys that are hammering your wallet. Maybe you should buy a little town car to tootle around town, and keep the XK for weekends on the highways.
#16
US owners can more readily afford to run more thirsty cars, but we here in the UK are paying £6 a UK gallon. I just came back from the supermarket, and filled up there using a loyalty voucher for 5p off a litre. One litre is up at £1.389, which gives a gallon price of £6.08 with the discount !! I am very tempted to go for a diesel XJ this year. OK, the fuel costs more, (like £1.449 a litre, but you can get well over 30 mpg in town and over 40 mpg on highway runs.
#17
#18
Agreed!! Gas mileage was the last thing on my mind when I bought my XKR. When family/friends ask me what kind of mileage I get I tell them I have no idea and don't care. They look at me like I have two heads!
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intdiamond (03-19-2013)
#19
I think that for the type of driving you are describing, that poor MPG is not out of line. Basically, by not exceeding 35 MPH you never even get into higher gears to give you any mileage. It is the worst kind of driving for MPG, outside of going uphill and slow.
My driving is just the opposite; almost all freeway and no stop and go. I get about 26 US MPG with my 4.2 XK and 25+ with my 5L XJL. Both are accumulated values for several thousands of miles. It is the driving in the highly over-driven 6th gear that should bring your MPG up from the sub 10s. But, since you are never in 6th gear, MPG suffers.
Albert
My driving is just the opposite; almost all freeway and no stop and go. I get about 26 US MPG with my 4.2 XK and 25+ with my 5L XJL. Both are accumulated values for several thousands of miles. It is the driving in the highly over-driven 6th gear that should bring your MPG up from the sub 10s. But, since you are never in 6th gear, MPG suffers.
Albert
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intdiamond (03-19-2013)
#20
I have hinted to some inherent flaws of the direct injected motor that are sure to bite jag owners sooner or later. That is the problem of carbon buildup on the intake valves.
Most manufacturers have shifted to Direct Cylinder Injection, and opened this bag of worms, and many other brand owners (Audi, Lexus) have filed complaint after complaint on the subject. So much so that they, and many Indy shops now offer a cleaning solution that is recommended yearly.
I recommend you research "carbon buildup in direct injection engines") and read up on subject.
Not that this is what is happening to you, but it is known for causing decreased performance and fuel economy.
Vince
Most manufacturers have shifted to Direct Cylinder Injection, and opened this bag of worms, and many other brand owners (Audi, Lexus) have filed complaint after complaint on the subject. So much so that they, and many Indy shops now offer a cleaning solution that is recommended yearly.
I recommend you research "carbon buildup in direct injection engines") and read up on subject.
Not that this is what is happening to you, but it is known for causing decreased performance and fuel economy.
Vince
Last edited by CleverName; 03-19-2013 at 12:08 PM.
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intdiamond (03-19-2013)