Infiniti kicked off its G Line of luxurious sports sedans in 1990, a series that is still in production today under the Q Line. However, the G35 series that was in production from 2003 to 2008 brought a special blend of premium amenities and serious sporting capability, which is what we’re focused on today.
Built-in sedan, coupe, and convertible form, the G35 benefits from the reliability of its Nissan underpinnings. But as with any vehicle, the Infiniti G35 has had its share of ups and downs. So, we’ve put together this list of best and worst model years to help you decide where to look when you’re ready to buy.
| Best Years | Why? | Worst Years | Why? |
| 2007-2008 |
Well-executed 4th-gen series |
2003 |
Challenges with launch of 3rd-gen model |
| 2004 |
Increase in FIXD and Owner Reliability Scores |
2005-2006 |
Reliability lows and upkeep cost highs |
Infiniti G35 Engine Reliability Score, Safety Ratings, MPG, and Value v.s. Maintenance & Repair Costs Year by Year
The first chart below, Infiniti G35 Reliability Score, is the main driver of our model year rankings. It is a combination of objective FIXD device data and subjective owner-reported information. Typically the first year of a new generation – like 2003 – will struggle with reliability as the kinks are worked out, which is reflected in the chart.
From there, we normally blend in published government safety scores from the National Highway Traffic Safety Administration (NHTSA) and fuel efficiency figures per fueleconomy.gov. However, in the case of the G35, the only year that the NHTSA performed crash testing was 2008.
As a result, the safety chart below only shows industry-wide safety scores, which we’ll touch on below. Fortunately, the Insurance Institute for Highway Safety (IIHS) has regularly tested the Infiniti G35 as we discuss in the relevant sections below.
We also incorporate market values from Kelley Blue Book (KBB) against owner-reported annual maintenance costs. That goes into the ranking decision along with owner survey answers and pertinent safety recalls. Lastly, with details on safety recalls and common Diagnostic Trouble Codes (DTCs), we can create the final rankings below.
If you’re in the market for a car, take a look at our article on the USA’s most reliable and cheapest to repair cars in the U.S. Don’t get stuck with a lemon, use our data to help you shop.
Engine Reliability Score – Over The Years
The FIXD Reliability score (green line) is based on the number of CELs thrown by each model year. After tallying them up, we weight this objective score by mileage and convert it into a 1-10 scale where 10 is the best and 1 is the worst.
By asking G35 owners, “How reliable would you say your car is?”, we can pull together a subjective reliability score for comparison. This multiple-choice question offers answers from “Just Point A to Point B driving” to “I could take a cross-country trip, no problem.” After converting the answer into a 1-10 scale, we create the Owner Reliability Score (gray line).
As you can see, the objective and subjective reliability scores mostly move in the same direction. But occasionally, like in 2005 and 2006, the scores diverge somewhat. This highlights the aforementioned owner sentiment versus objective reality and illustrates why it’s important to consider both scores.
You can find out more about our reliability scoring process at the bottom of this article and learn about some of the most common CELs to expect from Infiniti.
NHTSA Safety Score – Over The Years
The gray line on this G35 NHTSA Safety Rating chart illustrates the average safety score across the automotive industry. Normally, we would have access to a published overall safety score for a vehicle like the Infiniti G35 from one year to the next. However, the NHTSA did not rate the G35, except in 2008.
Though there is not an overall rating for that year, it’s worth noting that the 2008 G35 earned 5 out of 5 stars for the front driver and both side impact tests, while the front passenger score came in at 4 out of 5. Relevant details from the IIHS crash test protocols are discussed in the model year sections below.
Understanding how a given model year of the G35 ranks for safety is important as it plays a big role in keeping insurance premiums down. If you live in one of the states listed below, we can show you the cheapest vehicles to insure in yours.
| What Used Cars Are the Cheapest To Insure In: |
| Ohio |
| North Carolina |
| Michigan |
| Georgia |
| Texas |
| New York |
| Illinois |
| Pennsylvania |
| California |
MPG – Over The Years
By averaging the combined fuel economy figures – from fueleconomy.gov – across all trims of each model year, we can create the above Infiniti G35 Average MPG chart. As you can see, the figures don’t vary much which is unsurprising considering the G35 was powered by a Nissan VQ-series V6 engine throughout its production.
The bump-up in fuel efficiency between 2006 and 2007 coincides with the arrival of the all-new 4th-gen G35. For 2007, the 3.5L V6 was heavily revised with new internals and an updated VVT system. Even though it also made more power, the net effect was better fuel economy.
Current Market Value of All Infiniti G35 Years & Cost Per Year to Repair and Maintain Each
This chart plots current Infiniti G35 market values from KBB against annual maintenance costs per owner surveys. It’s a valuable set of data points in defining why some model years are best avoided. For example, values flatten out and maintenance costs spike between 2005 and 2006, which is one reason these G35s are on our list of models to avoid as we dive into below.
When shopping for a used Infiniti G35 it’s important to keep in mind that not all vehicles are cared for equally. To protect yourself from lemons, take along a FIXD Sensor on your test drive. FIXD connects to a free app on your smartphone to tell you more about the vehicle you’re checking out, including check engine lights and other hidden issues that the owner or dealership may be attempting to hide. Click here to learn more and get FIXD for only $19.99 (regular price $59)!
Important Features Timeline
1996: Final year of 1st-gen G20 sedan production
1997: G Line goes on hiatus
1998: Second year without G Line production
1999: 2nd-gen G20 debuts, larger all around, new rear suspension
2000: 2.0L I4 powertrain gains power and new transmissions
2001: Leather and sunroof made standard on G20t model
2002: Sport package brings body-color front grille and 16” alloys
2003: G35 debuts as 3rd-gen G Line with RWD, 3.5L V6 power, and coupe option
2004: Heated seats made standard, AWD offered on sedans
2005: Interior upgraded with higher-quality materials, new Sport version of coupe
2006: Bluetooth becomes standard, active rear steering offered on coupe
2007: 4th-gen sedan debuts with revised powertrain and evolutionary styling
2008: 4th-gen coupe arrives as G37 with new 3.7L V6
2009: Sedan adopts G37 name and engine, convertible variant debuts
2010: Mid-cycle refresh of front fascia, trim materials, and navigation system
2011: Short-lived G25 and Infiniti Performance Line models introduced
2012: Carryover year with no major changes
2013: Low-cost G25 dropped from lineup
2014: End of the G Line, replaced by new Q Line models
The Best Years of the Infiniti G35
Taking into account FIXD and Owner reliability, government safety scores, fuel efficiency, and G35 owner survey responses, we’ve come up with this list of the best Infiniti G35s. Pertinent recall information and notes about common DTCs are included as well.
2007-2008 Infiniti G35
FIXD App Engine Reliability: 2-3/10
Owner-Reported Reliability: 7/10
KBB Value: $5,098-$5,701
Fuel Economy: 20 mpg
Annual Maintenance/Repair: $417-$972
In 2007, Infiniti released the 4th-generation G35 sedan. It was still powered by a 3.5L V6, but the changes went deep including more power, a new VVT system, upgraded engine internals, a revised automatic transmission, a stiffer chassis, and a new rear-wheel steering system.
Typically when a new vehicle generation debuts, particularly with such a comprehensive overhaul, reliability suffers. However, that is not the case here. Instead, the FIXD Reliability Score marched steadily upward to a high point in 2008, while the Owner Reliability Score stays strong at 7 out of 10 in both years.
All that powertrain work also resulted in more efficiency with the average fuel economy bumping up to 20 mpg in 2007. Market values hit a high point in 2007 but considering it is under $6,000, these G35s are a solid purchase value as they average 139,000 miles.
2008 was the only year that the NHTSA crash-tested the G35 and it earned top marks in all categories except front passenger where it came in at 4 out of 5 stars. Looking at IIHS safety testing, both the side impact and head restraints/seat categories improved versus 2006 and the G35 earned a “Good” in the front overlap test – the highest available mark.
Other highlights include an all-time low average annual maintenance cost of just over $400 in 2008 and a positive owner outlook on durability. Though these G35s have as much as 50,000 miles to go before hitting the 200,000-mile mark, between 24 and 31 percent of owners are confident it’ll happen.
In 2007 a more aggressive Sport package debuted across the lineup and in 2008, the coupe variant arrived with a burlier 3.7L V6. This performance-minded engineering clearly drew in the enthusiasts as owners were two to three times more likely than average to use their G for “fast driving”.
On the whole, the Infiniti G35 is an expensive vehicle to own with an overall average annual maintenance bill of $900 and a 91% likelihood of requiring a $500+ repair. Though these 2007 and 2008 models run well below the average annual time in the shop, be aware that replacing brakes is the most likely culprit.
Two of the three most common DTCs for these G35s are P0420 and P0430. Both indicate the catalytic converter is on its way out, something you learn more about in this DTC P0420 explainer video. To save some money on the potential $2,000 repair bill, be sure to check out our DIY DTC P0420 guide.
DTC P0455 is another frequent troublemaker that has to do with a leak in the Evaporative Emission Control (EVAP) system. Fortunately, this is often caused by a loose gas cap, an easy fix.
There were three recalls issued by the NHTSA for the 2007 Infiniti G35 and one of them, related to non-deployment of the passenger airbag, impacted 134,000 vehicles. The single 2008 recall was along the same line, specifically a malfunctioning Occupant Classification System that could interfere with airbag deployment.
An Infiniti dealer should repair any outstanding safety recall work on a vehicle up to 15 years old. You can use this NHTSA VIN tool to determine if your G35 has any open issues.
2004 Infiniti G35
FIXD App Engine Reliability: 2/10
Owner-Reported Reliability: 7/10
KBB Value: $3,422
Fuel Economy: 19 mpg
Annual Maintenance/Repair: $700
2004 marked one year after the all-new G35 arrived and it brought a notable improvement in reliability versus the 2003 model that is our pick for the very worst G35. The FIXD Reliability Score stepped up by one point in 2004 and the Owner score jumped up two points.
This is all the more impressive when considering these G35s are nearly 20 years old and average 190,000 miles. And yet, time spent in the shop each year is less than half the two-day average plus maintenance costs come in $200 under the average of $900.
That correlates with only 33% of owners saying their G35 is expensive to repair versus an average of 50% for this metric. But if an expensive repair does arise, there’s a 20% chance of it being engine-related. This is not surprising when looking over the DTC data.
DTC P0300, one of the most common causes of a CEL on the 2004 G35, indicates an engine misfire has been detected. It likely means you need to replace the spark plugs as we talk about in this DTC P0300 explainer video. Expect to pay about $200 at a shop or save some money by going the DIY route with the help of our DTC P0300 guide.
DTC P0021 is also engine-related, specifically, it has to do with the intake camshaft timing being too advanced as part of the VVT system. If DTC P0430 pops, it may be time for a new catalytic converter, which runs between $1,500 and $2,000 to replace.
A relatively high 29% of owners use their 2004 G35 primarily as a family vehicle. This is noteworthy because an AWD option debuted in 2004 and anyone with a family would be happy to have the added peace of mind that comes with the added traction AWD provides.
There were only three recalls for the 2004 G35. The most impactful was an issue with the fuel filler hose developing a crack that affected about 192,000 vehicles.
The Worst Years of the Infiniti G35
Working with the same information to determine the best Infiniti G35s, we’ve compiled a list of model years to avoid. You can expect more issues with reliability, higher maintenance bills, and in some cases lower safety ratings with these poor-performing G35s. This ranking moves from the very worst models to the “best of the worst”.
2003 Infiniti G35
FIXD App Engine Reliability: 1/10
Owner-Reported Reliability: 5/10
KBB Value: $3,209
Fuel Economy: 19 mpg
Annual Maintenance/Repair: $500
Twenty years ago, Infiniti debuted the all-new G35. It was larger and more luxurious than the outgoing G20, not to mention swapping FWD for RWD and a four-pot for V6 power. Riding on Nissan’s Z-car platform, it was an exciting entry into the premium segment. Unfortunately, the reliability wasn’t where it needed to be.
As often happens with a new vehicle launch, the powertrain and associated running gear had teething problems. That’s the case here with all-time low scores for both the FIXD and Owner Reliability Scores.
Owner-experience sentiment is also on the low side with below-average agreement that the seats are comfortable and above-agree agreement that the seats are uncomfortable. And even though these models average 183,000 miles, most owners don’t think their G35 will make it past 200,000.
Other dings against these early G35s are poor market values, above-average days in the shop each year, and seven recalls – the most of any model year. One of those recalls is related to a weld issue on the crankshaft and/or camshaft position sensor. It affected over 600,000 vehicles and aligns with the tally of the most common DTCs.
Specifically, DTC P0345, which means the camshaft position sensor is malfunctioning. This severe issue should be addressed immediately as it monitors the position and rotational speed of the camshaft, a critical engine component.
Another common trouble area on these G35s is with the ignition coils. As indicated by DTC P0300, expect to replace the spark plugs if this code lights up. Our DTC P0300 guide will help with the DIY approach or you can take it to a shop and pay around $200.
And if you see DTC P0307, there is a problem with an oxygen sensor heating element. Figure on $150-$300 to have this issue fixed at a shop.
Given all these engine-related trouble codes and the recall issue, it’s not surprising to learn that the 2003 G35 has a 33% chance of an expensive repair being due to the engine. This is the highest of any model year and three times more than the average. Bottom line – avoid the 2003 Infiniti G35.
2005-2006 Infiniti G35
FIXD App Engine Reliability:1/10
Owner-Reported Reliability: 7/10
KBB Value: $4,411-$4,464
Fuel Economy: 19 mpg
Annual Maintenance/Repair: $893-$1,200
Toward the end of 3rd-gen production, G35 reliability took a dive with the FIXD score dropping to the lowest possible figure in 2005 and staying there through 2006. As well, market values went flat during this stretch and annual maintenance costs spiked to $1,200, which is $300 above average.
In safety testing, the IIHS rated both models as Poor for the head restraints and seat protocol, while the 2006 G35 was just Acceptable in the side crash test. Fortunately, there was only one recall in 2005 and two in 2006 with a malfunctioning front airbag being the most significant issue in both years.
It’s also notable that cabin improvements implemented in 2005 were successful as 26% of 2005 owners – more than twice as many in 2003 – report finding the seats comfortable. But, these upbeat details are far outweighed by the objective reality of keeping these G35s on the road.
The 2005 model spends over three days in the shop each year with the 2006 model coming in just under that figure even though the odometer readings only average between 125,000 and 139,000 miles. And with a 50% likelihood of causing an expensive repair, brake replacement is an area to watch for.
This brake issue was the impetus behind a proposed nationwide class action lawsuit that consumers filed against Nissan for the 2003 and 2004 G35. It resulted in Nissan amending its warranty to cover brake pad and rotor replacements and is likely partly responsible for causing a high incidence of brake repairs on the 2005 model.
Another unfortunate high point is the 33% chance of an expensive repair on the 2005 G35 being related to the transmission. This is more than six times higher than the average and points to the importance of staying on top of your transmission service.
As for CELs, DTC P0011 is the most likely culprit. This issue with the VVT system is severe and means the intake camshaft timing is incorrect. DTC P0462, which is one of the top five most common trouble codes for the G35, indicates an issue with the fuel level sensor.
If DTC P0300 lights up, it means an engine misfire has been detected and it’s time to replace the spark plugs. We dive deep into this issue in our DTC P0300 explainer video. You can also learn how to go the DIY route with this DTC P0300 guide.
FAQs
What years of the Infiniti G35 have engine and/or transmission problems?
The 2003 Infiniti G35 marked year one of 3rd-gen production, which likely contributed to it having the highest likelihood out of all model years – 33% – of an expensive repair being engine-related. On top of that, there was a major recall for critical engine components issued that year, which correlates with one of the most common DTCs for 2003.
As for transmission problems, watch out for the 2006 G35. On average, there is a 5% chance of a $500+ repair being transmission-related across all G35 model years. That figure jumps past 30% for the 2006 model, so if you have one be sure to stay on top of the transmission service.
What is considered high mileage for an Infiniti G35?
On average, you can expect an Infiniti G35 to show 158,000 miles on the clock with 190,000 miles being a high point across all model years according to our surveys. Given that, 140,000 could be considered high mileage for an Infiniti G35 as it will likely allow for another 50,000 miles of driving before the engine is on its last legs.
Owner-sentiment points to a high point of 200,000 miles as 26% think their G35 will go that far versus just 4% who don’t. However, these are older cars, so you’re better off relying on objective data. Consider installing a FIXD Sensor before buying to get a full picture of what’s going on with your potential G35.
What other vehicles should I consider?
As is frequently the case in the luxury sports sedan segment, Infiniti was aiming at the Germans when it launched the G35, namely the BMW 3-Series, Audi A4, and Mercedes-Benz C-Class. But the Lexus IS and Cadillac CTS are also worth consideration as is the Nissan Maxima, which the automaker has long described as a “four-door sports car”.
What owners of the Infiniti G35 like to use their car for:
| Frequent Use Categories: | How Useful? (Out of 5 Stars) |
| Family Vehicle | **** |
| Lots of Driving (travel/long commute) | **** |
| Hauling/Towing | * |
| Office on Wheels | * |
| Sport/Fast Driving | ** |
| Luxurious Driving | ** |
| Outdoor/Off-Road | * |
A Note About Data and Information Sources
This article has many details about Infiniti G35 reliability; here’s what we used for our assumptions and recommendations.
- FIXD Reliability Score & Data: Engine reliability information is captured via the FIXD App.
The FIXD Reliability Score is calculated using the number of DTCs per year, weighted by mileage. This is then turned into a scale of 1-10 for easy graphing.
This is an objective score.
- Owner Reliability Score & Data: This data is the result of surveying Infiniti G35 owners who use FIXD.
The Owner Reliability Score comes straight from owners of the Infiniti G35.
This is a subjective score.
To determine the Owner Reliability Score we ask each car owner:
How reliable would you say your Infiniti G35 is?
a. Just point A to point B driving
b. A Daily Commuter
c. Good for a 100-mile road trip
d. Good for a 500-mile road trip
e. I could take a cross-country road trip, no problem
From here we translate their answers into the Owner Reliability Score:
a. = 2
b. = 4
c. = 6
d. = 8
e. = 10
Keep in mind, owners may think their car is more or less reliable than it actually is.
One potential problem is that people often buy the same make or model they are used to when they go car shopping, just a newer year.
Ford, for instance, has a number of consumer loyalty awards for the Ford F-Series, Ford Mustang, and Ford Expedition.
Car owners may be so loyal to the make or model they currently own that they would have trouble accurately comparing their cars’ reliability to others.
It’s for this reason that we ask car owners a question that is relative to mileage rather than relative to other cars.
Still, be mindful of the accuracy of these Owner Reliability Scores, people’s perceptions and unconscious blindspots can skew data.
We suggest looking at both the FIXD Reliability Score and the Owner Reliability Score for this reason.
- KBB Value: Average private-seller valuations as supplied by Kelley Blue Book (KBB), based on an Infiniti G35 with typical mileage for that respective model year.
- Fuel Economy: Mileage-per-gallon estimates according to the EPA MPG on Fueleconomy.gov
- Annual Maintenance/Repair: Upkeep expenses as reported by surveyed Infiniti G35 owners
- Safety Rating: Crash test data collected and reported by NHTSA. We average all ratings for each year to come up with a simplified, average safety score. This makes it easier to look at on a graph.
References
- Infiniti G35 model-specific information. Retrieved July 12, 2023, from https://www.edmunds.com/
- Infiniti G35 model-specific recall information. Retrieved July 12, 2023, from https://www.nhtsa.gov/recalls
- Infiniti G35 model-specific information. Retrieved July 12, 2023, from https://www.auto-brochures.com
- Class action lawsuit information. Retrieved July 12, 2023, from https://www.theautochannel.com/news/2004/10/11/249116.html
Niel Stender grew up doing replacement work on his old Cherokee and sweet Mitsubishi Starion, which led to a degree in mechanical engineering and a job at Ford as a vehicle dynamics engineer. His writing infuses that automotive background with sales and marketing experience. Writing about cars for close to a decade now, he enjoys digging into some of the more technical mechanical systems under the hood and throughout a vehicle.
